FLOWERY BRANCH — Talk about a costly victory for the Atlanta Falcons.
Linebacker Sean Weatherspoon became the third starter placed on injured reserve Tuesday after a win over the St. Louis Rams, though he will be eligible to rejoin the roster in Week 11.
The Falcons (1-1) used the one-time-only designation that allows an injured player to return, but Weatherspoon won't be able to practice for six weeks and can't play in a game for eight weeks.
The announcement came one day after the Falcons placed defensive end Kroy Biermann (torn right Achilles tendon) and fullback Bradie Ewing (separated left shoulder) on the reserve list with season-ending injuries.
Also in doubt: running back Steven Jackson and cornerback Asante Samuel, who both left in the first half with what were described as thigh injuries.
At the very least, the Falcons know they must replace two key players on the defensive side.
Weatherspoon, a first-round pick in 2010, quickly established himself as the leader of Atlanta's defense. He had 13 tackles this season and 306 in his career. Biermann has 16½ sacks in his career, including four last season, and had taken on the expanded role of outside linebacker when the Falcons went to a 3-4 alignment.
"As I say many times, one man's misfortune is another man's opportunity, and we've got some guys that we expect are going to step up and make some plays for us," coach Mike Smith said Monday.
Replacing Weatherspoon is particularly troublesome, however, because linebacker is the team's thinnest position.
There are only four other linebackers on the roster, including two undrafted rookies. The Falcons have greater numbers at defensive end, but getting pressure on the quarterback has been a long-standing trouble spot and there's no one else on the roster with even Biermann's modest credentials.
Smith was not available for comment Tuesday, an off day for the players, and generally does not provide injury updates before Wednesday unless a player is going to be out for a significant amount of time.
The Falcons travel to Miami to face the Dolphins (2-0) on Sunday.