Per the Mirror:
The German side are desperate to keep their star striker after losing Bundesliga player of the year Shinji Kagawa to Manchester United, and are said to have already rejected a £17m offer from Stamford Bridge.
Lewandowski, 23, is one of the rising stars in world football and a player with enormous potential. Most recently, he starred on Poland's Euro 2012 squad, where he scored one time in three matches.
He has spent the last two club seasons with Dortmund and has enjoyed a lot of success with the club, and he has also proven that he's ready for the challenge of the Premier League.
At 6'0" and about 171 pounds, Lewandowski doesn't have amazing size, but he is a strong player who can withstand the physical play of English football.
His shooting accuracy and shot power are very good, and his football intelligence is also impressive. Lewandowski probably won't be a player who could start for Chelsea right away, but after a few matches of Premier League experience, he would settle in nicely.
If the Blues want to add another attacking player who is young and talented during the current transfer window, Lewandowski is the right man. He would have a great career at Stamford Bridge.