City fear Matt Clarke could be missing from action for up to a month with his damaged calf.
The dominating defender, whose time at Valley Parade has been jinxed by injuries, was forced to hobble off after less than half an hour at Aldershot on Saturday.
It was a double blow for Stuart McCall, who saw his previously all-conquering side beaten 3-2 by a spectacular late goal from substitute Scott Davies.
McCall admitted: “Sometimes calves can keep you out for anything between two and four weeks. It depends on the severity of it but it’s disappointing for Clarkey because he’s started the season ever so well.
“But it opens the door for Mark Bower now to come in and stake his claim. It is tough to come on when he did and get into the pace of the game when the other team are on top but I thought he acquitted himself well.”
Fellow centre half Graeme Lee also needed five stitches in a head wound and played the second half in a bandage.
Lee said: “It wasn’t ideal with me running round groggy and Clarkey off. Touch wood it was more of a precaution to take him off than anything.
“But we’ve got good cover and I think Bowser did really well. It’s always nice to have a settled side but there’s no problem if we have to change it.”
McCall felt City warranted a draw after bouncing back from Peter Thorne’s penalty miss but he had no complaints about the quality of two of the Aldershot goals.
He said: “We were done by two smashing strikes from a good side. I knew how difficult it was going to be because Aldershot have a great spirit and play good football.
“They’ll beat a lot of teams down there but I thought our display in the second half merited enough to get a point.
“We were fortunate to go in ahead at half-time because they were the better side and we needed to up it. I thought we did that. We looked more dangerous and played a lot better football than we had done but football is so often about thin dividing lines.
“It’s disappointing to lose our unbeaten record but we’ll have to bounce back from it. You’re going to get setbacks like this and it’s not a disaster.”
Sights will now switch to tomorrow night’s derby at Leeds in the Johnstone’s Paint Trophy, although McCall is just as focused on the league trip to Lee Sinnott’s Port Vale next weekend.
He said: “We’ll regroup and see who’s available before picking a team for Leeds. It’s a local derby against our rivals and we want to put on a good show and give a credible performance.
“But, being me, I’m already looking forward to next Saturday because it’s very important that we bounce back in the league.”