Lennon has been sidelined since December after he picked up the problem that threatened to rule him out for the season.
The 22-year-old has missed the last 19 outings in all competitions, however suggestions had surfaced that the former Leeds man could be in contention to take on Portsmouth in the FA Cup semi-final on Sunday.
Spurs boss Harry Redknapp told supporters in a question and answer session that his wing wizard would be closely monitored by the club's medical staff.
"Today is the first day Aaron has joined in a training session, it's his first morning back," said the 63-year-old boss.
"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."