Koscielny has been sidelined since the beginning of May when he ruptured his Achilles during Arsenal’s Europa League semi-final clash with Atletico Madrid.
The Frenchman was forced to miss his country’s World Cup triumph in Russia because of the heartbreaking injury.
Koscielny was forced to undergo surgery to fix the problem and wasn’t expected to return to action until the end of the year.
However, in a major boost for new Gunners boss Unai Emery, Koscielny has returned to training ahead of schedule.
The centre-back was filmed walking onto the training pitches at London Colney as his rehabilitation continues.
And while many fans were delighted to see his return, some supporters noticed something worrying.
“Still limping, nowhere near ready,” one fan wrote.
Another said: “He ain’t walking right .. :/.”
“Is he limping right foot?” a third fan commented.
A fourth supporter said: “Still limping a bit. Welcome back boss.”
Boss Emery admits that while Koscielny’s return to the training field is positive, the club need to be patient with their key defender.
“He’s working very hard,” Emery said. “First he was in France.
“He came back to us last Sunday.
“We are happy to have him here with us, because he’s our captain and he’s showing us his spirit to stay with us.
“We need to be patient with him because the injury was an important injury.
“It’s clear that it’s very important to stay with us, working here and showing us that he wants to help us.”