07/23/2013 10:46 EDT | Updated 09/22/2013 05:12 EDT

Argonauts release linebacker Brandon Isaac and place Kackert on injured list

TORONTO - It was a good news-bad news kind of day for Toronto Argonauts head coach Scott Milanovich.

His star quarterback may have escaped serious injury, but it looks like his standout running back will be sidelined for a while.

Milanovich said Tuesday that Argonauts quarterback Ricky Ray, the CFL's leading passer, is day-to-day with the knee injury he suffered in last week's road win over Winnipeg, while running back Chad Kackert, last year's Grey Cup MVP, is gone four to six weeks due to the knee injury he sustained versus the Bombers.

"Ricky is day-to-day, he's significantly better than he was a year ago," Milanovich told reporters Tuesday. "It'll probably be a later in the week decision . . . but it's not nearly the severity it was a year ago (when Ray was out with an injury to the same knee).

"Chad Kackert is going to be a little longer. We're anticipating four-to-six weeks as an estimate. Obviously it can go either way . . . that one is a little bit worse."

Toronto also released veteran linebacker Brandon Isaac. It was a surprising move given Isaac was a team captain and just one of five starters back from last year's Grey Cup-winning defence.

"This decision was made by the coaching staff that we think gives us a chance to be a little better at that position," Milanovich said. "I do appreciate what Brandon's done and what he can do as a football player.

"Sometimes you have to make hard choices that you think somebody else can do the job a little better."

Milanovich said the club will look at giving youngsters Josh Gatlin and Jamie Robinson a shot at taking the vacant position but could also have new players in camp soon to challenge for it.

Ray missed nearly a month last season after spraining the same left knee in a game. Should Ray be unable to play July 30 when Toronto hosts B.C. at Rogers Centre, Milanovich said he has a replacement in mind but wouldn't say if it would be Zach Collaros or Trevor Harris.

When Ray was hurt against Winnipeg, Milanovich had sophomores Collaros and Harris both take snaps for the remainder of the game.

"They're both doing a fantastic job and they're both working hard at it," Milanovich said. "They've both been in games now, which is a good thing.

"It's the reason why we felt comfortable enough not to bring Jarious (veteran backup Jarious Jackson) back. Obviously he had a great opportunity in B.C. but we also felt like these young kids had a chance to grow and move into that role. If Ricky is not able to go then they're going to have to really prove it against a great defence."

Jackson served as Ray's backup last season before retiring as a player and joining the Lions as their quarterback coach in the off-season.

Fortunately for the Argos (2-2), they have the benefit of time. Toronto doesn't return to action until Tuesday when it hosts the B.C. Lions at Rogers Centre.

With Kackert out, rookie Curtis Steele will move into the starting lineup against B.C.

"We've got a lot of confidence in him," Milanovich said. "We've been trying to prepare him for this because you never know, when you're the backup tailback anything can happen.

"Certainly it's tough (losing Kackert) . . . we have to do a good job as coaches giving (Steele) a chance to be successful."

Rookie defensive lineman Nekos Brown, who opened the season as a starter, and offensive lineman Michael Di Domenico were also released while the club added defensive backs Ricardo Colclough and Hugo Lopez and running back Chris Jennings.