The 22-year-old has been one of Saints' standout players since their relegation to npower League One, leading to speculation that a move to Birmingham or Stoke could be in the offing this January.
Lallana's contract at St Mary's runs out at the end of the season but Le Tissier has advised the attacking midfielder to stick with Saints for the time being.
"I mean, being completely honest, I'd probably advise him that the Premier League is not the place for him just yet," he told Press Association Sport.
"I think I'd need to see him have a real strong season in the Championship before I would be convinced that he could make an impact in the Premier League."
Le Tissier also praised Lallana's contribution to the side, adding: "I don't think it was any coincidence that the five games we went without scoring were the fives games Adam Lallana missed this season. He's obviously a huge part of the team."