The Argentina international was absent from Wednesday's group session at the club's Sant Joan Despi base amid claims that he has a problem with his adductor.
Catalan station TV3 reported yesterday that Messi is now a fitness doubt for Barca's first game back after the coronavirus crisis, a trip to Mallorca on June 13.
However, the Evening Standard claims that the 32-year-old's injury is nothing serious and he always planned to train separately in the gym on Wednesday.
Barca's players were given a day off on Thursday and are scheduled to return on Friday.
Messi scored 19 and set up 12 goals for the La Liga leaders before the league was brought to a halt in early March. body check tags ::