GAVIN MAHON will return to the squad for the FA Cup fourth round clash with West Ham tomorrow (Saturday) in a game Aidy Boothroyd sees as a dress rehearsal for the crunch league clash at Upton Park next month.

The captain missed Tuesday's win over Blackburn with a calf strain but he will be in the 16 for the trip to east London.

Boothroyd must then decide whether to break up the Al Bangura-Damien Francis midfield axis which performed so tigerishly against Rovers. The likelihood is though, that Mahon - Watford's player of the season, according to the manager - will replace Bangura.

Dan Shittu underwent a scan on Wednesday to discover the extent of the new injury he sustained midway through the first-half and he is expected to miss the game. Jay DeMerit, the match-winner against Blackburn, will partner Malky Mackay at the heart of the defence.

Will Hoskins and Lee Williamson are both cup tied but Williamson suffered another injury blow last week. Having only recently recovered from a broken toe, the midfielder was knocked unconscious and lost a tooth following a sickening clash of heads with Moses Ashikodi in a practice match last week.

"We had an 11-a-side and there was one of those horrible aerial challenges," explained Boothroyd. "The two players smashed heads and unfortunately Lee come off much the worse, he was knocked out and he lost his tooth. That just shows the competitiveness of the training. It's unfortunate for Lee as he's going to miss out for a couple of weeks now."

In light of the uplifting effect that Tuesday's result is likely to have had on the squad, Boothroyd admitted he would prefer tomorrow's game to be a league fixture and said: "I would prefer it to be league game but it's not. We now go to West Ham in the Cup and it's a good chance to get some more winning momentum.

"We approach it no differently," he added. "I will field our strongest team and look to try and win the game.

"I'm not sure whether they will play their full-strength team or not. They have got a different manager and some new signings who will be wanting to make their mark.

"It might be a preview to the league game there. It will be hard. They have got a big enough squad where they can rest a few and we haven't.

"It's just important for us to maintain what we did on Tuesday night and if the Cup helps us do that then great."