The signing of free-agent left tackle Andrew Whitworth last week gave the Rams a fix to one part of an offensive line that was a major liability in 2016.
They also are taking steps to shore up the middle.
The release of center Tim Barnes last week cleared the way for the Rams to seek an alternative.
The Rams have signed restricted free agent center Ryan Groy to a two-year offer sheet. The Buffalo Bills, for whom Groy has played the last two seasons, have five days to match the offer, which reportedly includes $3.5 million in guaranteed money.
Groy, 26, started seven games for the Bills last season. Buffalo tendered him as an original-round selection, so the Bills would not receive any compensation if he signs with the Rams.
Groy, 6-foot-5 and 320 pounds, played in college at Wisconsin and originally signed with the Chicago Bears as an undrafted free agent in 2014.