Middleton (ankle) has been ruled out for Thursday's game against the Grizzlies, Eric Nehm of The Athletic reports.
Middleton hasn't been cleared for 5-on-5 work and remains without a return timetable, but the Bucks continue to treat him as day-to-day. Taurean Prince continues to start at small forward in Middleton's absence, while the latter's next chance to suit up will come Saturday versus Cleveland.