The Chilean has still not fully recovered from his thigh problem, while the Blaugrana's second-choice goalkeeper has picked up an ankle injury in training
Alexis has been struggling with a thigh problem of late and was forced to sit out last weekend's derby win over Espanyol at Camp Nou.
The Chilean is back running, but he is training alone as he bids to work his way up to full fitness.
Pinto, meanwhile, sat out Friday's session after injuring his right ankle and is now set to miss the trip to Seville.
There is even a fear that the goalkeeper, who has been filling in for Barca No.1 Victor Valdes in recent weeks, might not be fit for the May 25 Copa clash with Athletic Bilbao at the Vicente Calderon.
Barca's meeting with Betis at the Benito Villamarin on Sunday gets underway at 22.00CET.