Drum in time with game old doctors travelling north (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Drum in time with game old doctors travelling north T (=time) + AMBOUR (RU=game, i.e. rugby union + O (=old, as in OT) + BMA (=doctors, i.e. British Medical Association); “travelling north” indicates vertical reversal)