The Barcelona star was ruled out for between six and eight weeks after sustaining a hamstring tear in the first half of his side's 4-1 La Liga victory over Real Betis on November 10.
This represents Messi's third muscular injury of the season, and means he will not play again this calendar year.
His return had been pencilled in for Barca's first Liga game after the mid-season break against Elche on January 5 but, speaking after being presented with the European Golden Shoe in Barcelona on Wednesday, Messi said that while his condition is improving, he is not setting a particular target for a comeback.
"It's getting better - it's not hurting anymore," the 26-year-old stated.
"I'm not putting any specific dates (on his return). If everything goes to plan, I'll be back (against Elche).
"I just want to get fit again, I don't want to force my body. I just want to be able to play relaxed again."
Messi - who is now the first player to ever be awarded the Golden Shoe, which was inaugurated in 1967-68 and is awarded to Europe's top goalscorer, three times - went on to insist that criticisms over Barca's style of play under new coach Gerardo Martino are wide of the mark.
Even though the defending champions sit top of La Liga having taken 37 points from a possible 39 this term, Martino has been slammed in some quarters for supposedly abandoning Barca's renowned tika-taka approach.
However, Messi stated: "We haven't changed our philosophy. We have different options, but we are faithful to Barca's style."
Messi won the 2012-13 Golden Shoe after netting 46 league goals to help Barca reclaim the title from Real Madrid and dedicated his award to his family, friends and team-mates.
"Obviously I'm really happy, it's a really nice prize. (But) it's a prize for the whole team - it's a group award," he added.
