Chelsea's summer recruit Kalodou Koulibaly suggests Romelu Lukaku struggled in the Premier League, due to a lack of 'confidence'.
The 31-year-old centre-back completed a move to Stamford Bridge from Serie A earlier this summer - before Lukaku completed the reverse move as he secured a loan back to Inter Milan.
Koulibaly, who knows Lukaku well from their time playing against each other in Italy, suggests that there could have been issues in the Belgian's 'private life' that caused on-pitch struggles.
Speaking in his press conference on Wednesday, the former Napoli defender said: 'Romelu is a good player, a nice player, a talented player.
'He is very strong and I was used to playing against him in Italy – I think he didn't like to play against me!
'Last year I think maybe he didn't have the confidence he needed to play like he wanted. Maybe something else, I don't know.
'Football is not all about the pitch, it is also your private life and everything else, so maybe it was something that didn't work with him over here.'
Lukaka completed a club-record move worth £97.5m to Chelsea last summer from Inter Milan - but failed to adjust to Premier League life after scoring just eight league goals before returning to Italy this summer.
Looking ahead to this year, Koulibaly said: 'We have a lot of talents, a lot of good players, a lot of winners, a lot of experienced players, a lot of young players. I wish Lukaku a good season but I wish Chelsea a better season.'
The Blues are already on the search for Lukaku's replacement, after they opened talks with Barcelona as they are interested in signing Pierre-Emerick Aubameyang before the transfer window closes.
Chelsea have already acquired the services of Raheem Sterling but Thomas Tuchel is eager to add another forward to his ranks following the departure of Lukaku.
