Barcelona will look to put a domestic slip-up aside and focus on its Champions League defense with a tough group opener against AC Milan.

Real Sociedad rallied from a two-goal deficit to draw 2-2 with the Catalans on Saturday following weeks of speculation that Barcelona would face few challengers as it vies for a fourth straight Spanish league title.

Defensive lapses were Barcelona's foremost problem in San Sebastian and it will now go up against the Serie A champions' potent attack, with Zlatan Ibrahimovic returning to the Camp Nou for the first time since the Sweden striker's turbulent exit before last season.

Barcelona centerback Carles Puyol should return for the first time since May after recovering from knee surgery.