Atletico are unable to register any new players this summer having had their appeal against their transfer ban rejected by the Court of Arbitration for Sport (CAS) earlier this month, meaning Costa would not be able to feature until January if he did complete a move back to the club before the start of next season.
'In terms of an all-round striker, proven to have scored goals with Everton a year ago and the last two or three seasons in the Premier League, he would be an option for them.
"I think he is a fantastic striker, we've all seen that since he arrived at Chelsea", he told Sky Sports of Diego Costa. I'm sure they will look at the player in the same type as Diego Costa. "If Chelsea do lose him, they will have to make sure they get the right signing to keep going forward".
Chelsea have been strongly linked with a move for prolific former striker Romelu Lukaku, who has excelled at Everton.
The Belgium worldwide revealed earlier this month he had reached "an agreement" with another Premier League side, but refused to name the club.
Everton striker Romelu Lukaku has played down rumours linking him with a return to Chelsea.
Lampard continued: "I know Lukaku from playing with him".
"He didn't really get the chances but he's certainly developed a huge amount since he left the club".
According to ESPN, Lampard said: "Antonio would be their most important signing - for me he was their man of the season".
The Everton striker had another fine season in 2016/17, scoring 25 Premier League goals to finish runner-up to Tottenham's Harry Kane in the race for the Golden Boot.