Born in Munich, Bavaria, Lell started his training with FC Alemannia München,[1] He earned a place in Bayern's youth section in 1993,[1] and played there for eight years.

[5] Lell made his Bundesliga debut[6] on 4 October 2003 in a 4–1 against Hertha BSC where he came on as a substitute for Michael Ballack in 84th minute.

After the 4–2 loss to Wacker Burghausen on the second matchday, Lell fell out of favour with manager Huub Stevens.

[15] In the 2009–10 season, new Bayern coach Louis van Gaal relegated Lell to the reserves, where he made an appearance.

[16] Seven years after making his debut with first team, he left the Bavarian side and signed for Hertha BSC on 23 June 2010.

[17] This ended a 17-year connection dating back to 1 July 1993 when he joined Bayern Munich's youth academy.

[18] His contract in Berlin ran for one year, and was automatically extended for an additional two as Hertha earned promotion to the Bundesliga.

Lell quickly established himself as an important part of Hertha's defense, starting almost every fixture and assuming vice-captaincy of the team.

[21] The decision to part company with Lell came a day after he was given a five-match ban for insulting referee Wolfgang Stark during a relegation play-off match against Fortuna Düsseldorf.