Nigel Pearson has expressed confidence that West Bromwich Albion's Premiership survival bid will not be undermined by the likelihood of West Ham United playing a weakened side against one of their relegation rivals.

Pearson, the club's assistant manager, yesterday said he thought the Londoners would field as strong a side as possible in tomorrow's match with Portsmouth - who trail Albion by six points with nine games remaining.

But with Albion playing Manchester United tomorrow and Pompey taking on an exhausted West Ham side that gap could narrow - particularly if the Hammers chose to rest key players.

Which they might do having gone to extra time in the FA Cup replay with Bolton Wanderers on Wednesday night, when Marlon Hare-wood's late winner put them into the quarter-finals.

With their last-eight match to be played on Monday evening - only 48 hours after the Premiership game - manager Alan Pardew could rest several of his players given their relatively comfortable position in the league. Following the 2-1 victory Pardew complained that his team had insufficient time to prepare for another two matches in three days and claimed his squad was 'struggling'.

Pardew followed that up with: "I want to do what's right for West Ham and I've got some hard thinking to do."

But Pearson has rejected suggestions that Pardew would not do right by Albion, saying: "Alan is a professional man, I am sure he will do the right thing.

"It has only been intimated that he will make changes but I don't know what side he is going to put out. I would hope they put out as strong a side as they can.

"I am sure there are regulations over it and they will have to deal with them. They will be aware of them."

He also maintained that whatever West Ham did, it would not affect the situation in which Albion find themselves.

"It is something that we have got no control over," Pearson said. "First and fore-most we have got to look after our own performance at Manchester United and do what we can do in the games we play."

United's visit to The Hawthorns this weekend means a return to the scene of his most famous triumph for Kieran Richardson. The leftsided midfielder was a key part of the Albion team that defied the odds - and gravity - to escape relegation on the last day of 2004-05.

Richardson scored the second goal in a 2-0 win in the last game he played for Albion before going back to Old Trafford at the end of a four-month loan spell.

Tomorrow will be the first time he has come back to the club since and Pearson believes he will be coming back an even better player than when he left.

"He is a player we would have liked to have kept but having said that - in terms of his personal development - his time here has obviously helped him out immensely. We are delighted he has progressed in the fashion he has.

"He is a single-minded individual. He always had it in his mind that he was coming here to get regular football to force his way back into Man United's side. Good on the lad, he is a very ambitious player."

Pearson said Paul Robinson would be fit to face United after injuring his knee in last week's 1-1 draw with Birmingham City but the game will come too soon for Zoltan Gera, however, despite his 65-minute run-out in his second successive game for Albion reserves on Monday.

Meanwhile, Albion have signed the biggest sponsor-ship deal in their history with telecommunications company T-Mobile. The present deal -which began in 2004 - will be extended until summer 2008 and gives the Baggies the option of a further extension.