The U’s make the short trip down the M40 to Wycombe Wanderers bidding to end a five-game winless run.
Scott Davies and Josh Ruffels in particular stood out, while several first-team regulars were given a rest.
Dave Kitson, Danny Rose and Ryan Williams all dropped to the bench at The Valley and Nicky Wroe also comes into the equation after being ineligible in midweek.
It is a far cry from many games this season, when injuries left United with barely 11 senior players.
Lewis thinks it will be a difficult call.
United’s assistant manager said: “We’ve played different shapes in the last couple of games, so we could go either way.
“There are a few decisions to make, but whoever plays, the good thing is you know we’ll have a strong bench as well.
“At times we have had a really young bench. That’s fine, we’ve had to rely on young players and they have done when they’ve come in.
“Look at Josh Ruffels the other night, I thought he was outstanding.
“We know we can rely on those players, but it is good to have a really good bench.”
United’s drop in form has left them playing catch-up in Sky Bet League Two for the first time this season.
Lewis knows how important it is to rediscover the winning habit quickly, but insists there is no cause for alarm.
He said: “There’s 22 games to go, everyone has little blips and we just have to make sure now we start getting some wins.
“As always your experience tells you that the teams above you will lose games as well.”
- JAKE Wright was an option to take over as goalkeeper if Ryan Clarke got into trouble at Charlton Athletic in midweek.
The U’s brought in Jonathan Henly on an emergency loan last week due to injuries to Max Crocombe and Wayne Brown.
But the Reading goalkeeper was ineligible for the FA Cup tie at The Valley, having registered after the date of the original game.
United did not name a back-up on the bench – which could be repeated in Tuesday’s replay.
If Clarke had been forced off, either Wright or Johnny Mullins were in line to put on the gloves.
Mickey Lewis, United’s assistant manager, said: “It was discussed and not too many people put their hands up.
“I think it would have definitely been Jake, or Mulls.”