Wasn't there myself, but IIRC, Joe Corrigan was injured in the 1st half in a League Cup tie at Stoke early in the 1980/1, soldiered on until half time but didn't come out for the second period. Tommy Booth replaced him in goal.
We'd gone 1-0 down early in the game, before Corrigan even picked up his injury, and that was still the score at the interval. The game ended in a 1-1 draw, so we lost the first half, with our international 'keeper available, and won the second half, when our centre back replaced him. Another typical City event! :)