The experienced midfielder has nothing but praise for the prolific attacker and has voiced his disappointment with Mario Gotze's imminent transfer to Bayern Munich
Lewandowski has been in sublime form in the 2012-13 campaign, with his four goals against Real Madrid on Wednesday the highlight of his season so far, and Kehl believes the striker deserves to be compared with the very best.
"For me, Lewandowski is the best striker in Europe. Scoring four goals in a semi-final against Real Madrid is a dream come true. It's incredible how easy he makes things look. Robert makes the difference," Kehl was quoted as saying by Bild.
"I think that his performance against Madrid has significantly increased his market value. I hope that he will still play with BVB next term."
Lewandowski has a contract with Dortmund until 2014, but is widely expected to leave the club this summer, with Bayern Munich sitting in pole position to sign the 24-year-old ahead of Manchester United.
Kehl is hopeful that Lewandowski does not follow Mario Gotze out of the club, admitting that news of the Germany starlet's move to rivals Bayern was a bitter pill to swallow.
"I needed some time to deal with the news and I must admit that I was quite disappointed with it," Kehl revealed.
"However, that's the way things go in football. We also managed to sign Marco Reus last year because of a buy-out clause.
"There are not many players like Mario around, but I am confident that we will find an alternative. We have always done well in the transfer market in the past few years."