If B1 fouls A1 and is replaced, can B1 return during A1's free throws?

Once a player is replaced after committing a foul, they are not allowed to return to the game until the next opportunity to substitute arises, which in this case is after the free throw situation concludes. Specifically, if B1 is substituted out after fouling A1, B1 cannot re-enter the game until a stoppage in play occurs following A1's free throw attempts. This rule is in place to ensure game flow and the clarity of player participation regarding fouls and substitutions.

This means that during A1's free throws, B1 must remain on the bench and cannot return to the game until A1 has completed their free throws and play has resumed. The idea is to maintain a clear structure and fairness within the game rules, preventing teams from manipulating free throw situations by instantly reintroducing players who have previously committed fouls.