Nevin hopes the summer signing from Atletico Madrid can keep up this form for a sustained period.
Costa has made four competitive appearances for the Blues so far and has scored seven goals in the Premier League to help Chelsea maintain a 100% Premier League record at the start of this season, and Nevin believes the forward could become one of the most memorable players the club has had.
In his column on the official Chelsea website, Nevin wrote: "I don’t use the word legend often, some bandy it about with abandon, but in many ways it should be kept sacred, not treated lightly. Legends are the likes of Osgood, Zola, Terry, Drogba and Lampard. There are many, but not that many and to enter that pantheon it takes years’ worth of quality at the very highest level, so be restrained.
"It can take players years into their time at a club to be considered in that bracket and that is the way it should be. Even so, it seems clear to me that our new striker has everything to grab a place in our house for historical heroes. To do so, he has to stay at the club, stay fit and stay hungry, and have long periods of good form. It is a lot to ask, but now and again we get a feeling for a player at Stamford Bridge and already he feels like family, indeed he feels like a favoured son. Long may it continue."
Costa was brought in as the man to score the goals for Chelsea as last season there wasn't a prolific striker in front of goal for the Blues. Given that they got to the Champions League semi-final and within four points of the Premier League title last season, Costa's difference this season could be huge.
If he has the desired impact over a sustained period of time, he is sure to go down as one of the club's greatest if he keeps up this prolific form in front of goal, and it has a large part in Chelsea's success.