The striker suffered a knee injury in training just before the start of the season and is yet to return to action for Everton.
The Toffees are keen not to rush him back and are prepared to give him all the time possible to get himself fit and ready to get back into the team in the coming weeks.
He has been gradually building his fitness and has retained the support of Lampard, who stressed that Calvert-Lewin is still a top striker and he is prepared to help him get back to his previous levels.
The Everton boss stressed that his contributions were vital last season and is aware of what he will bring to the team once he returns to fitness.
Lampard said in a press conference: “He’s a top-level striker.
“He knows he’s got support and advice from me. I know what he can give us because of what he gave us last season.”
Anthony Gordon decided to stay put at Everton despite interest from Chelsea in the summer and the club are keen to offer him a new deal.
Lampard claimed that talks are ongoing between Everton and the winger’s representatives over him signing on improved terms.
He said: “The club are speaking to Anthony and Anthony’s people to see if we can get the right solution.”