Chelsea midfielder Jorginho believes Frank Lampard "skipped some steps" and was not ready to become head coach at Stamford Bridge.
Lampard, the club's record goalscorer, was appointed by the Blues ahead of the 2019-20 season, having impressed with Derby County in the Championship.
The former England star guided Chelsea to a top-four finish in his first season as a Premier League boss, as well as the FA Cup final where they were beaten by Arsenal.
But there were few signs of progress by the time Lampard was sacked in January of this year, with the team in ninth, and he was replaced by Thomas Tuchel.
Lampard picked up 1.67 points per game across his Chelsea reign, the fourth-lowest mark among the club's Premier League managers.
No Blues boss has seen his team average fewer goals in the competition, with Lampard's side scoring 1.35 per game.
Only five Chelsea players appeared more times in the league under Lampard than Jorginho (42), while his seven goals also ranked sixth in that time.
But despite being a key man in that side, Jorginho felt Lampard's inexperience told.
"Look, I'll be really sincere here on Lampard," he told ESPN Brasil.
"I believe, given he was a legend at the club, he skipped some steps necessary for learning before moving to a big club.
"He came to a club where he is a legend, without having experience at other clubs. I think he came too soon, skipped a few steps ahead and wasn't ready for a job at this level, to be honest."
Chelsea have since lost only two of 20 matches in all competitions under Tuchel, the second of which still secured their Champions League progress against Porto.
Tuchel's side are through to the semi-finals in Europe, as well as climbing into the top four in the league and reaching the FA Cup final.