According to L'Equipe, the double Olympic champion resumed training with his club Paris Saint-Germain on Saturday (22 May) and travelled with the first team as they defeated Aix-en-Provence in the French Starligue on Sunday.
Karabatic underwent surgery on his right knee on 28 October and has been gradually rejoining his teammates over the past few weeks, but an official date for his return hasn't been decided yet, the French newspaper reports.
The 37-year-old, who's been inactive for several months, is now racing against time to recover his match fitness.
The PSG centre-back is pursuing a fourth EHF Champions League title with four different teams and admitted that the Final Four in Cologne on 12-13 June represents "a motivation for the end of the season".
Karabatic is also looking to find his best form ahead of France's Olympic training camp starting in Creteil on 23 Juin.
Before Les Bleus qualified in Montpellier in March, he told Tokyo2020.org: "I don't know if I'll be 100% fit but that's my goal. I want to be ready to prepare for the Games and have the chance to fight for a place in the team."
The 1.96m-tall player has collected over 300 caps with his national team, winning three Olympic medals (two golds, one silver), four World and three European titles.
French coach Guillaume Gille is expected to announce his final list by 5 July.