The Catalan giants have been without the Argentinian, winner of the Ballon d'Or for the last four years, since November 10 when he limped off in the first half of the 4-1 La Liga win over Real Betis.
The 26-year-old forward has returned to his home country for further treatment and was the subject of a visit from key Barcelona officials on Wednesday.
And the club say the signs are positive, with Messi on the verge of moving on to the next stage of his rehabilitation.
"On Friday further tests will be performed to establish when he can begin the third phase of his recovery programme," a Barcelona statement read.
"(Doctor Ricard) Pruna, along with director of sport Andoni Zubizarreta, travelled to Argentina on Tuesday to get a first-hand look at the progress being made by Leo Messi.
"The striker injured his hamstring on November 10 in Seville and since November 29 has been working on the second phase of his recovery programme in his home country.
"He started working under supervision of doctor Daniel Martinez and kinesiologist Luis Garcia, members of the medical team that works with the Argentina national team.
"He was later joined by FC Barcelona physio Elvio Paolorosso, as had originally been planned."
In the absence of Messi, Brazilian forward Neymar has stepped up, scoring six goals in the club's last three matches.
Barcelona top the Liga table on goals scored ahead of Atletico Madrid, with Real Madrid five points adrift in third.
