To put it simply...very high.
There have been many talented footballers that have graced Stamford Bridge over the years, but very few will go down as the "greats." To be a great is not just to be a top player but to continue that over your career and perform at the top level for your club over many years.
Frank Lampard has achieved things at Chelsea that very few midfielders have managed to accomplish at any club in the world.
He is third among Chelsea's all-time top scorers—which is a feat in itself—but add to that the fact that these goals have come from midfield, and this statistic becomes even more incredible.
Now at 34 years old, Lampard is coming to the end of his Chelsea playing career, but the fact that he is still an integral part of the Blues' midfield is testament to his consistency.
But Chelsea is a club that can boast a number of legendary players, so Lampard has competition in the "greatest of all time" category.
Players like Gianfranco Zola, Peter Osgood, Didier Drogba, Ron Harris, Bobby Tambling, John Terry and Kerry Dixon, to name a few, have already cemented their statuses as greats with the club's fans.
In my opinion, Frank Lampard is an even bigger great than all of these players, and looking at that list, that is a massive statement.
Is Frank Lampard Chelsea's greatest player ever?
Peter Osgood is known as "The King of Stamford Bridge," and nobody will ever take the title from him, but with all that Lampard has achieved with Chelsea, you have to put him at the top.
He has won everything there is to win with the Blues, and you have to believe that these trophies may not have been Chelsea's to win had it not been for the influence of Lampard.
The fans know how important he has been (and still is) to the club, and banners with "Super Frankie Lampard" can be seen draped all over the stands in Stamford Bridge.
Although he didn't begin his career at Chelsea, Lampard is now a Blue through and through, and the news that he wants to manage the club one day (via Sky Sports) could even further cement his place in the Chelsea Hall of Fame.
So, Chelsea fans, let's take a moment and thank Super Frankie Lampard for all he has given to Chelsea, and let's look forward to what else he has to offer us in the future.