A man whose ablution breaks on Friday

Al-Hasan was asked: If a man's ablution breaks at the time of the Friday prayer and, when he comes back after making ablution, the imam has already finished the prayer, what should he do? Al-Hasan said: He should pray four rak'ahs.

Waki' said: I asked Sufyan: If a man began the Friday prayer with the imam, but his ablution broke and he went to make ablution, and when he came back the imam had already finished the prayer, what should he do? He said: If he has not spoken to anyone, he should pray two rak'ahs.