He was initially ruled out for around three weeks after suffering the injury during a 4-2 win over Sevilla.
Messi, 31, was included in the squad to travel to Italy this week and reports in Spain suggested the Argentina maestro was keen to feature in order to boost his Ballon d'Or aspirations before next month's award ceremony.
Coach Ernesto Valverde said on Friday he did not rule Messi out of playing against Inter, but said he was concerned about rushing the player back, especially as his side are on a winning run without their usual talisman.
'In terms of his play and his movements, he's fine.
"There are three or four possibilities that we're studying".
Rihanna Shuts Down Use Of Her Music At Donald Trump’s "Tragic Rallies"
Earlier she had tweeted urging Florida residents to turnout and back Andrew Gillium, the Democrat candidate, to be state governor. Axl Rose of Guns N' Roses also expressed frustration his music was being played at political rallies.
"He could play at the start, come off the bench, not play at all ... everything is possible".
For the past decade, Cristiano Ronaldo has basically been given free rein on the pitch so we would have loved to be a fly on the wall when it was decided that the Juventus forward would not take every free-kick for his new club.
Barca lead Group B with nine points from three games heading into Tuesday's fixture in Milan, ahead of Inter (six points), Tottenham (one) and PSV Eindhoven (one). "We would like to win, of course, because [we've not qualified] yet". "We also have to give credit to the opponent, who are in need of points. We're seeing them create very little but be efficient with the chances the do have".