It was announced last week that Stephen Thompson had suffered an injury and had pulled out of his UFC 154 bout against Besam Yousef. 
The UFC has announced today that Matt Riddle will replace Thompson in the fight against Yousef and the fight will take place on the preliminary card of UFC 154.
Riddle (6-3, 1NC) recently came off suspension after a positive drug test following his UFC 149 win over Chris Clements. He tested positive for marijuana and received a 90 day suspension and his win was over turned and was declared a no contest. Following the news of his positive drug test, Riddle sent out a tweet of his medical marijuana card that is from the state of Nevada.
Yousef (6-1) signed with the UFC after winning his first six professional bouts and made his debut at UFC on FUEL TV 2 against Simeon Thoresen and was defeated by submission in the second round. During his career, five of his six wins are by knockout or submission and his last two victories are by submission.
UFC 154 takes place on November 17th from the Bell Centre in Montreal and will be headlined by a welterweight title unification bout as welterweight champion Georges St-Pierre meets interim welterweight champion Carlos Condit.