Both the Blues and Manchester United have been linked with the striker that finished second in the Golden Boot race with 25 goals in 37 appearances.
However, Nicol, a former Liverpool defender, isn't convinced Lukaku will be able to fill Diego Costa's role, with the Spaniard reportedly on his way out.
"Lukaku for me doesn't fit into a team that predominantly spends most of the time in and around the opposition's box, he's a guy that needs space in my opinion," Nicol said on ESPN FC.
"If you look at Chelsea last year, one of the things I loved watching was Costa and (Eden) Hazard together, playing little one-twos and playing with each other in a small space.
"Lukaku can't do that so if they do get Lukaku, that would change a lot for me the way Chelsea attack."
