Tommy Rowe is Doncaster Rovers doubt as back problem threatens his involvement against Cambridge United
Rowe suffered a back spasm and was substituted just eight minutes into the 3-2 win against Cheltenham Town, and may struggle to be part of his team's attempt to win back-to-back League One games for the first time since March.
Rovers will leave it as late as possible to decide if he can play at home to Cambridge United.
Taylor has suffered the inevitable niggles that come after returning to the side having missed pre-season and a large chunk of competitive football.
"He's not felt great over the weekend," Wellens said of Rowe. "He won't train today (Monday) so we'll give him as long as possible but I would say he's going to be very doubtful.
"He's just got a ligament problem in the bottom of his back and it needs freeing up and there's no real timescale of when it's going to free up. He's not moving well at the moment.
"We'll give him as long as possible because he's a big player for us. But if he's not right it gives someone else an opportunity."
Winger Taylor's experience also makes him an important member of a young squad but his comeback game at home to Wycombe Wanderers earlier this month has been his only appearance under Wellens.
"Tayls will be out he's had another setback," revealed Wellens. "Where he's had the operation, he's got some nerve problem within the scar tissue.
"I've had it myself and my view was I needed to train to get it freed up but Jon just wasn't comfortable doing it."
Right-back Kyle Knoyle returns from suspension.