Arsène Wenger has been encouraged by Wilshere's ability to "absorb games" since his 17-month lay-off and the midfielder believes he is edging towards his best form.
"I had never been injured, so how long it will take for me to come back is hard [to say], but I feel good," Wilshere told Arsenal Player.
"On Wednesday night [against Montpellier] we started the game off sloppily, and I was one of those who kept giving the ball away. That's tough when you come back and start badly in a game. But we've got great players here and they keep you going.
"Percentage-wise, I'm probably 80 to 85. I'm feeling better and better with every game and I think I heard the boss say at Christmas you'll see me back to my best. I think that's probably a reasonable timescale."