Who plays the friend Worm whose gambling debts Mike McDermott is forced to pay back in the film 'Rounders' from 1998?

Explanation

'Rounders' (1998) is a popular poker film. The lead character, Mike McDermott (Matt Damon) is a young man, who is forced back into the poker world to make enough money to pay off his friend Lester 'Worm' Murphy's (Edward Norton) gambling debts. Worm was supposed to have been a smoker, but non-smoker Edward Norton vehemently refused.