Marc Bircham in his QPR playing days

Millwall assistant manager Marc Bircham has left the club to take up a role with MLS side Chicago Fire.

Bircham made the revelation in the wake of the Lions' 1-0 win at Nottingham Forest on Saturday, the victory at the City Ground proving to be a superb send-off for the 36-year-old.

He played more than 100 games for the club before leaving for QPR, where he kicked off his coaching career and spent five years on their backroom staff before returning to The Den.

First-team coach Nigel Gibbs will step up to become Ian Holloway's assistant after Bircham's departure.

Bircham told the club's website: "This was a very hard decision to make because I really feel there are good times ahead for Millwall under Ollie.

"But I had almost gone to the MLS earlier in my career, and this time, when the chance came up, it just seemed like such a great opportunity for myself and my family.

"I'm sure Millwall will stay up this season and I will always look forward to coming back to The Den."

The club's CEO Andy Ambler added: "We wish Marc the very best with his new venture. He goes with our blessing and thanks for his hard work over the past year."