Phifer was a starter for the Rams from 1992–1998. In 1992 Phifer made 66 tackles (51 solo) and defensed six passes. Phifer led the Rams in tackles in 1993 from his "Will'" or outside linebacker position. In the summer of 1994 the restricted free agent Phifer signed a tender-offer of $649,000. However, since Phifer and his agent felt there were no negotiations he was reluctant to sign a further deal. Phifer had another solid season in 1994. However, during the confusion of the Rams moving from Los Angeles to St. Louis, Phifer signed a four-year, $8.5 million contract that includes a $2.5 million signing bonus. He was the Rams' Ed Block Courage Award winner in 1995. He was also a Pro Bowl alternate in 1995 and led the Rams in tackles 1995 with 125 to go with his 3 sacks, 3 interceptions a forced fumble and a fumble recovery. He again led Rams tackles in 1996 with 122, when he was again voted a Pro Bowl alternate.