Chelsea great Frank Lampard believes Romelu Lukaku is a good option to replace Diego Costa, but feels the Spain international's departure will be a blow.
Costa claimed head coach Antonio Conte no longer wanted him at the Premier League champions, despite his 22 goals in 2016-17.
Lukaku, 24, has regularly been linked with a return to Stamford Bridge after four strong seasons at Everton.
Lampard said the Belgium international would be a fine replacement, but added there were other possibilities.
"I know Romelu from playing alongside him, it was early on in his career and he probably didn't get the chances in his first spell at the club," he told Sky Sports.
"He's certainly developed to a huge degree since he left the club, Romelu would certainly be a good option. The only thing Chelsea have to look at is the inflated market that is around now, it makes it very tough.
"In terms of an all-round striker, he's proven to have scored goals at Everton, but there are others. I'm sure they'll try and get a player in the same mode as Diego Costa that can give them a physical presence and 20 goals a season."
Costa scored 20 league goals in two of his three seasons at Chelsea, helping them to the title in 2014-15 and 2016-17.
Lampard believes the Spain international's exit would be a blow, saying there were few like him.
"He's a fantastic striker and we all saw that last season and since he's been at Chelsea. He would be very difficult to replace, there's no doubt about it," the former England international said.
"I don't know where Diego Costa's mind is, whether he wants to leave or not, that's all speculation. One thing that is for sure, is that you've got a great striker in him.
"So, if he stays, brilliant, if he doesn't, then you'll have to go to the top end of the world's strikers to replace him. He's an all-round physical presence that also has the quality to get goals, that's not easy to find in the modern day."