Colin Todd admits City will be tested to the limit without Dean Windass and Lee Holmes.
Both players will miss tomorrow night's home clash with Carlisle after limping off at Swansea.
Todd will be forced into making changes - and fears the lack of depth in his senior squad could be exposed.
"It might be the weakest side I've put out this season but you can't legislate for injuries," Todd said.
"Whatever side goes out there against Carlisle will be hoping to get back to winning ways.
"But we're going to be tested to the limit if Dean (bruised calf) and Lee (twisted ankle) cannot play."
The 1-0 loss at the Liberty Stadium was City's second on the road in a week - a double setback which has knocked the gloss off a good start.
City defended well under pressure but frontmen Eddie Johnson and David Graham failed to trouble Swansea keeper Willy Gueret.
The best chance of an equaliser fell to Steve Schumacher in stoppage time.
The midfielder said: "I was gutted that went wide because I thought it was in all the way. The ball sat up well for me and I got a good clean strike but it just took a deflection off the defender's heel and went the wrong side of the post."
A frustrated Todd added: "We didn't have enough care on the ball and couldn't sustain pressure on their back four.
"It didn't help to lose two attacking players so early but we couldn't create enough opportunities and show that penetration.
"We were getting into their box pretty well at times but the final decision was wrong and there wasn't enough goal threat again.
"And their goal was a sucker punch because I thought we'd weathered everything they could throw at us.
"It's hard to accept because, like at Brentford the previous week, we did enough in the game to take something from it."
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