The 26-year-old has not featured for the club since November 10, when he was forced off in the 4-1 La Liga victory over Real Betis, and has been recovering in his native Argentina.
However, Barcelona, who return to action after their winter break against Elche on Sunday, confirmed on Thursday that the Argentina international is back training as expected.
"Messi is back! Training at Ciutat Esportiva," the Spanish champions stated on their official Twitter account.
If Messi does not feature on Sunday, he could make his return in Barca's Copa Del Rey clash with Getafe on Wednesday.
After the visit of Luis Garcia Plaza's men, the league leaders visit second-place Atletico Madrid, with the sides only separated by goal difference at the turn of the year.
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'Andy Robertson has a decision to make as a player, where you either roll your sleeves up and give someone great competition or you accept decisions and say that your time is done.' Alan Shearer on the conundrum facing Arne Slot's Liverpool
