Mascherano has been starved of first-team football this season, making just six La Liga appearances to date, and the lack of opportunities are said to be becoming a real frustration for the former Liverpool ace.
The 33-year-old, whose contract runs out in the summer of 2019, is believed to be considering his options and there will be no shortage of clubs eager to acquire his services.
Ernesto Valverde recently said the Argentina international would not be sold in the January transfer window but captain Messi has hinted his compatriot could be on his way out of the club.
"Mascherano? I'm not going to tell you what he told me, but I'll understand if he leaves, he wants to play more," he told TyC Sports. "I understand Masche. The best thing is to play and enjoy yourself, and he doesn't think he'll get minutes here."