Alcacer, who was used from the off in La Liga for just the seventh time this season in the absence of suspended striker Luis Suarez, insists that it is now a case of taking it one game at a time as Barca close in on the title.
"My job is to help the team, I've always said that. I'm a team player, I work for them and if I add a goal then great," he told reporters after the match.
"We knew how Athletic defend, we know their style, but getting two up in the first half allowed us to relax a bit in the second half and it's a good three points.
"Our mentality is the same every time we go out - go and win. We leave the table completely to one side and treat every game on its own and go out and win it."
Thirteen-cap Spain international Alcacer now has six goals to his name in all competitions this season.