The 20-year-old centre was given a formal warning for disorderly behaviour after jumping from a ferry into the harbour and was fined £3,000 by the Rugby Football Union.
"We will have a chat with Manu when he gets back to the club," Cohen told the Leicester Mercury. "It would be wrong to pre-judge any of the issues until we have spoken to him and seen what has been involved.
"But we will sit down with him and take into account the need to protect the image of the game, while also recognising any investigation and punishment that has been metered out in New Zealand.
"It would be a shame if anyone remembers Manu Tuilagi's time in New Zealand for anything other than what happened on the pitch."
Tuilagi was also fined £4,800 for wearing a branded mouthguard at the tournament.