But the Blues boss insists that with players of the quality of Robert Tesche (pictured) and Maikel Kieftenbeld likely to come in, he will still be putting out a side more than capable of winning the tie.
Rowett also indicated that 18-year-old striker Jack Storer could start following his impressive cameo appearance as a late substitute at the weekend against Cardiff City.
The only player definitely unavailable is Danish striker Nicolai Brock-Madsen, who is currently away on Olympic duty with his national side. On the injury front, midfielder Reece Brown has a slight groin problem and is likely to miss out against U’s and James Vaughan picked up a slight knock in training on Monday and will have a late fitness test.
"Whichever team we put out, I would expect they are able to win the game," said Rowett.
"Of course you want to give some of the players that didn't get an opportunity on Saturday such as Kieftenbeld and Tesche a chance. I don't think those two would weaken side at the moment.
"We've also got some youngsters that again may play from the start and it will be a really good opportunity for them to show what they're about.
"I think there's a possibility that Jack Storer and Josh Cogley might start. There's less of a chance of Reece Brown starting because he's just pulled his groin a little bit.
"He had a tight groin which was a carryover from the Kidderminster game and he just felt it a little, so again it's just a case of do we risk Reece tomorrow night?
"It's a shame because he would have definitely started the game, but we've got to be a bit cautious because we want him available for the games to come."