Siyar Bahadurzada has stepped up on short notice to replace Saffiedine against Lawler.
UFC officials made the announcement on Tuesday.
Bahadurzada (21-5-1) is a former Shooto middleweight champion. He was riding a six-fight winning streak when he made his UFC debut on April 14, 2012, against Paulo Thiago. The heavy-handed puncher knocked Thiago out in 42 seconds.
His seven-fight winning streak came to an end when he met Dong Hyun Kim in his next outing on March 3. Kim utilized his superior wrestling to take Bahadurzada down and keep him there throughout the course of their three-round fight.
Lawler (21-9-1) returned to the UFC and the welterweight division at UFC 157 in impressive fashion, knocking out Josh Koscheck in the first round.