Middleton (ankle) has been ruled out of Friday's game against the Knicks, Eric Nehm of The Athletic reports.
Middleton has yet to make his season debut, though he appears to be nearing a return to game action as coach Doc Rivers said Wednesday that the forward is progressing to 3-on-3 work, according to Nehm. Middleton's next chance to make his season debut will come Sunday against the Celtics, though he should be considered doubtful for any future contests until he's cleared for 5-on-5 work.