Lennon was back out with the squad in front of a healthy crowd at the Lane for Tuesday's training.
"Today is the first day Aaron has joined in a training session, it's his first morning back," Redknapp told the club's website.
"It was great to see him out training but we've got to take our time, it's important he doesn't break down and have another setback.
"We'll see how he goes this week, the physios will monitor his progress and they will let us know when he's ready to come back and start playing again. He's getting closer and that's good news."