New boss Roberto Mancini insists Manchester City must focus on the FA Cup, and not next week’s Carling Cup semi-final.

There is little doubt most Blues fans would trade elimination at Middlesbrough in the FA Cup third round on Saturday to guarantee victory over Manchester United in the first leg on Wednesday.

But Mancini is firmly focused on the Riverside. “I have told the players they should not be thinking about the semi-final,” said the Italian.

“We must have full attention on the FA Cup. We can prepare for the next game as soon as the final whistle goes.

“I will not be thinking about the match against United next week just what is best for the team and the players.

“I will play the strongest team I can at Middlesbrough but we do have a lot of injuries.”

Stephen Ireland is out for a fortnight with a hamstring injury – one of seven senior players definitely missing, including Kolo Toure and Emmanuel Adebayor, who are now on African Nations Cup duty with the Ivory Coast and Togo respectively.

Bellamy

In addition, Shaun Wright-Phillips is struggling to shake off an ankle injury that has prevented him appearing for Mancini so far, while Craig Bellamy’s knee problems mean he is unlikely to be risked, Mancini’s one concession to the United fixture.

“We do not have a very big squad so one or two young players who have been training with the first team might have to play,” Mancini added.

“I know Middlesbrough will be a tough side to play on their own pitch and will see the tie as one where they can relax and try to take the scalp of a Premier League team.

“We don’t want that to happen; we want to make progress because we know that by the time we reach the fourth round, a lot of our players will be back from injury.”

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Tottenham full-back Benoit Assou-Ekotto is set to miss most of January after suffering a groin strain.

Assou-Ekotto, 25, has withdrawn from Cameroon’s African Nations Cup squad and will have an injection next week, but it is understood he will not require an operation.

England winger Aaron Lennon has already been ruled out for a fortnight with a similar problem.

“Benoit is having an an injection on Monday,” manager Harry Redknapp said. “And he will be out for a few weeks.

“He has been terrific. Two terrific players, him and Lennon, have both picked up groin strains. It’s a big blow to us. They are two outstanding players.”

Gareth Bale is set to deputise for Assou-Ekotto at left-back but Redknapp has still not decided how to replace Lennon on the right flank.

David Bentley is an obvious choice but Luka Modric has returned from a fractured fibula, while Niko Kranjcar’s form has impressed.

Redknapp added: “I could play Krancjar and Modric wide. Modric could play on the right just as easily as on the left. The two Croatian boys are fantastic technicians and great footballers.”

Arsenal piled more misery on struggling Portsmouth as they cruised to a 4-1 success at Fratton Park.

Arsene Wenger’s men are firmly in the title race after an excellent recent run but cash-strapped Pompey, who are fighting a winding-up petition from HM Revenue and Customs, remain rooted to the foot of the table.

The Gunners took the lead in the 28th minute, but enjoyed more than a slice of good fortune in finding the back of the net.

Eduardo’s free-kick took a huge deflection off the unfortunate Younes Kaboul before beating Hermann Hreidarsson who had retreated to the line in a vain attempt to defend the post.

The Croatia international then had a hand in the second as the Pompey defence stood off the forward, allowing him to feed Aaron Ramsey, who immediately rolled it on to Samir Nasri to drill a low shot beyond Asmir Begovic before the break.

And Ramsey wrapped the game up in the 69th minute with the goal of the game, robbing substitute Anthony Vanden Borre before stepping away from another challenge and unleashing a superb shot from outside the box and beyond Begovic.

Pompey pulled one back soon after as Vanden Borre and Nadir Belhadj combined for the Algerian to fire home, but Arsenal restored their cushion as Alex Song was left unmarked to head home Nasri’s cross.

Fabregas

Wenger had confirmed before kick-off he expected injured captain Cesc Fabregas to be out for around 10 days with a hamstring problem – meaning the influential Spaniard would miss the FA Cup third-round tie at West Ham this weekend.

Pompey had beaten Liverpool here just before Christmas and started well as Kevin-Prince Boateng caused problems down the right and fired in a shot from a tight angle which Manuel Almunia beat away at the near post.

However, Arsenal looked dangerous on the break and Andrey Arshavin collected a loose ball before drilling a shot from 20 yards over.

Bacary Sagna’s cross from the right was glanced wide by Eduardo, before the Croatian got away down the left and laid the ball back into the path of Abou Diaby, who forced a good save from Begovic at close range.

Pompey captain Aaron Mokoena fouled Ramsey some 25 yards out in a central position – and it proved a costly error.

Eduardo drilled the 28th minute free-kick low, with the ball deflecting off former Tottenham defender Kaboul and past a static Hreidarsson on the right-hand post to give the visitors the lead.

Algerian midfielder Belhadj tried to relieve the pressure with a determined run and angled shot, which flew past the far post.

However, in the 42nd minute it was 2-0 when Song – who will not join up with Cameroon until the New Year – fed Eduardo in the left of the area. He pulled the ball back for Ramsey, who picked out Nasri – and the French midfielder drilled a low strike into the bottom corner.

Anger

To their credit, Portsmouth started the second half on the offensive and in the 52nd minute Belhadj flashed the ball across the six-yard box from the left.

The Fratton Park faithful chanted “where’s all our money gone?”, and cheered when captain Mokoena was replaced by Vanden Borre.

Hassan Yebda – another African Cup of Nations Cup departure – drilled a 20-yard effort straight at Almunia.

In the 65th minute there was a lengthy stoppage as Boateng needed treatment after falling heavily in the Arsenal penalty area.

The Portsmouth fans used the break in play to again vent their anger towards owner Ali Al Faraj as chants of “sack the board” and “you’re not fit to run a club” rang out.

But, in the 69th minute, the home fans were silenced when Ramsey robbed Vanden Borre and charged past Frederic Piquionne before lashing a left-foot shot into the net from the edge of the box.

The home side at least had something to shout about five minutes later when Belhadj converted a low cross from Vanden Borre.

However, hopes of an unlikely home comeback were ended 10 minutes from time when an unmarked Song headed in Nasri’s right-wing cross.

Manchester United brushed aside Wigan at Old Trafford as they smashed the Latics for five for the second time this season.

It was another masterclass from Wayne Rooney that helped the Red Devils to the emphatic 5-0 win as they closed the gap on Chelsea at the top of the Premier League.

The Champions were utterly dominant in Wednesday evening’s Old Trafford encounter and they took the lead just before the half-hour mark when Rooney scored his 15th goal of the season to put the hosts on their way.

Michael Carrick was the next to get his name on the scoresheet as he tucked home his third goal of the season before Rafael da Silva added a third just before half-time.

Dimitar Berbatov continued the romp within minutes of the restart before the star of the night Antonio Valencia wrapped up the win with a fifth 15 minutes from time.

United are now two points within Carlo Ancelotti’s Blues while the Latics, who seem ill-equipped to survive a relegation scrap, drop to 16th on goal difference.

Homework

Clearly, Wigan boss Roberto Martinez has not been doing his homework of how to play against United following Wednesday’s mauling.

Hammered by five goals on home soil in August, Martinez made the short journey across Greater Manchester for the return, committed to the same open style, which could quite easily get Wigan relegated.

The wonder was it took United almost half an hour to open their account.

A flurry just beforehand had involved Chris Kirkland turning a Rooney blockbuster wide and Paul Scharner booting a Nemanja Vidic effort off the line.

Following that, Rooney’s audacious shot from the most acute angle imaginable bounced back to Kirkland off the far post, the Wigan keeper having been completely bamboozled by the initial effort.

Finally, Berbatov, who had started the bombardment by racing onto Rooney’s through ball and getting chopped down in the box by Titus Bramble without winning a penalty, fluffed a chip when he was clean through.

At that stage, there must have been a temptation for Wigan to think they would survive. How foolish that would have been.

It will not cross Ferguson’s attention that much but an entire nation of football watchers is following his main man at the moment, crossing their fingers he can deliver World Cup glory to England.

Opener

Undoubtedly he is having his best season and it was the former Everton striker who stole in at the near post to meet Rafael’s cross and steer it past Kirkland to break the deadlock.

Three minutes later Carrick swept home the second after Valencia had shown enough vision to cut a pass back into his path rather than drill a cross into crowded penalty area.

On nights like these, the former Wigan man is a powerful force. And with Rafael charging forward on the overlap, the Latics could not resist.

Rafael’s only previous goal came in a disappointing defeat at Arsenal last year.

This time, after collecting Darren Fletcher’s pass and showing nimble feet to create space for himself on the edge of the area before drilling past Kirkland, he had more of a reason to celebrate with twin Fabio, who pumped the air with joy from the bench, although he was ultimately to share a pitch with his brother for the first time in a league game.

A change of keeper at the break as Mike Pollitt replaced the luckless Kirkland, failed to bring a change of fortune for the visitors.

Valencia skipped past Maynor Figueroa as if he was not there, then crossed into the space Hendry Thomas was supposed to be filling before he fell over. Berbatov controlled instantly and stabbed his shot into the far corner.

Memories of that nine-goal humiliation at Tottenham were coming back to haunt Martinez and his men.

If Rooney had managed to find the net when he got on the end of Berbatov’s chip instead of thundering a header against the bar, a repeat may have been on the cards.

Instead, United were forced to wait until the 75th minute, after Ferguson had made a triple substitution, for Rooney to drive into the heart of Wigan’s defences before sending Valencia through superbly to chip home a fifth.