Szczesny to miss start of Juventus campaign with thigh injury
Polish international Szczesny, who played 40 matches in all competitions for Juve last season, felt discomfort near the end of the first half in the 4-0 defeat by the Spaniards on Sunday.
"He underwent radiological exams this morning... which revealed a low-grade lesion of the adductor longus muscle of the left thigh," Juventus said, adding he could be out for 20 days.
Juve finished fourth last season in their second successive campaign outside the top three.
They open their Serie A campaign against visiting Sassuolo next Monday before games at Sampdoria (August 22nd) and at home to AS Roma (August 27th).
Carlo Pinsolgio (32) is set to deputise for the Polish international for the season opener.