Rizwan and Irfan both suffered hamstring injuries in the third match in Rawalpindi
Valencia, who hit the woodwork in the second minute, went ahead in the 24th with a well-taken finish from French forward Kevin Gameiro and doubled their lead with a powerful penalty from Dani Parejo in the 32nd.
Barca's insatiable captain equalised in the 64th with an unstoppable curling strike from outside the area, averting a first league loss for the league leaders since November and taking them on to 50 points from 22 games.
Ernesto Valverde's side are six points ahead of nearest challengers Atletico Madrid, who visit Real Betis on Sunday, and 11 clear of third-placed Real Madrid, who host Alaves on Sunday.