David Moyes has told Manchester United fans to expect more pain as he gets to grips with the mammoth task of replacing Alex Ferguson.

United have got off to a poor start in the Premier League under Moyes — they currently sit eighth in the Premier League after five games, having lost twice already.

The second of those defeats came last Sunday when the Red Devils suffered a harrowing 4-1 reverse at the home of bitter rivals Manchester City.

Wednesday’s League Cup third-round clash against equally bitter rivals Liverpool at Old Trafford represents an opportunity for United to bounce back.

However Moyes admitted on Tuesday that the transition between himself and Ferguson could be lengthy.

“I don’t think it was ever going to be the case this was going to be easy and smooth after Sir Alex,” said Moyes, who signed a six-year deal with United after leaving Everton. “There was always going to be days like this and there might well be more days like this.

“I hope not, but there will be because that is football. It was always going to be tough following such a great manager with a great team and I think people with real football knowledge will know there are probably some changes to be made.

“It is not going to be made in one fell swoop. It is going to be done in time. That is why the Manchester United board realised the job that needed to be done was a long-term one.”

Moyes must do without Robin van Persie as the Dutch striker has a groin injury.

Defenders Rafael and Phil Jones are doubts, but wingers Nani and Wilfried Zaha should get a chance.

Liverpool forward Luis Suarez is available after serving a 10-match ban for biting Chelsea’s Branislav Ivanovic last season.

There are four other League Cup fixtures on Wednesday night.

Arsenal travel to West Brom but will be without winger Theo Walcott, who missed Sunday’s win over Stoke and now requires surgery on an abdominal problem.

Walcott will miss England’s crunch qualifiers against Montenegro and Poland as well as Arsenal’s games against West Brom on Wednesday, Swansea and Napoli.

Arsenal manager Arsene Wenger said: Wenger said: “Theo will be out for a few weeks. He has developed some damage to his posterior abdominal wall. It’s not a hernia, but it’s a little structural problem in his abdomen.”

Elsewhere Birmingham, who are 18th in the Championship, take on in-form Swansea, Newcastle host Leeds at St James’ Park, while League One outfit Tranmere face Stoke at Prenton Park.