Zach Collaros will start in place of injured quarterback Ricky Ray when Toronto hosts the B.C. Lions on Tuesday.
Ray's status for the game has been in question since he suffered a lower-body injury in a 35-19 win at Winnipeg on July 19.
"I've been taking the reps all week so I was kind of expecting it," Collaros said Sunday at practice. "I'm just ready to go and I'm excited, it is my first start in a while."
Collaros, 24, spent most of last season on the injured list and sat No. 4 on the depth chart behind Ray, Jarious Jackson and Trevor Harris.
Collaros said he's looking forward to the first start of his two-year career.
"It's very special. It is a lot different than coming in in the fourth quarter. It is a completely different thought process and preparation before the game, so I'm just anxious and ready to go."
The Argonauts (2-2) enter a bye after Tuesday, which should give Ray time to heal.