The Saskatchewan Roughriders announced the signing of retired quarterback Drew Tate on Saturday, raising questions about the health of Zach Collaros.

Tate, 34, announced his retirement after nine CFL seasons with the Calgary Stampeders and Ottawa Redblacks this past June.

A native of Baytown, TX, Tate has thrown 410 completions for 5,008 yards and 35 touchdowns for his career in 48 games. He has also rushed for 24 touchdowns.

Tate was a member of the Stamps squad that won the 102nd Grey Cup in 2014.

Collaros, 30, left last weekend's 35-16 win over the B.C. Lions early after taking a hit to the head from Odell Willis. Willis was fined an undisclosed amount by the league for the play which they deemed a "high hit." It marked the third time this season that Collaros has left a game early after taking a hard hit to the head.

Riders coach Chris Jones said after the game that Collaros's early exit was simply a precautionary measure.

"He should be fine, but we pulled him just to be safe." Jones said. "[Collaros] took a good shot, a head-gear-to-head-gear shot; for precautionary reasons our trainers thought it was best to take him out of the football game, that's about all I know at this point."

His condition has not been updated since the October 27 contest.

Brandon Bridge and David Watford are also on the Riders' active roster.

The Roughriders are inactive during the season's final weekend with a bye. They finish the season at 12-6 and will learn their playoff fate following the Stampeders game with the Lions on Saturday night. A Stamps win or tie means the Riders will host the Winnipeg Blue Bombers in the West semi-final next weekend, but a Lions victory ensures a division title for the Roughriders and a bye into the Western final.