WINNIPEG — Zach Collaros knows his history of concussions raises concerns, but he's feeling healthy and ready to start for the Blue Bombers on Friday.

The newly acquired veteran quarterback will be under centre when Winnipeg (10-7) hosts the Calgary Stampeders (11-5) after starter Chris Streveler was put on the one-game injured list.

"I appreciate people's concerns, but I said this earlier, I trust the doctors and the specialists that we've seen," Collaros said after Winnipeg's walkthrough Thursday.

"Honestly, hats off to every doctor I've worked with throughout this whole process. This year has been a crazy year. Especially the (Toronto) Argos organization did a really good job of checking those boxes off. They were very thorough with it and I appreciate them for that.

"It definitely gave me some ease, and especially my wife."

Collaros was shipped to Winnipeg from the Argonauts at the trade deadline Oct. 9, insurance after Matt Nichols had season-ending surgery on a shoulder he injured in mid-August.

Collaros began his eighth CFL season with the Roughriders, but suffered a concussion during the first drive of the team's season-opening loss to Hamilton June 13. He was traded to the Argonauts in late July and never got into a game.

He also had two concussions in 2018, including Saskatchewan's final regular-season game, keeping him out of the West Division semifinal.

Streveler appeared to injure his right ankle late in Winnipeg's 37-33 loss to the Calgary Stampeders last Saturday.

"He needs another day," Bombers head coach Mike O'Shea said of Streveler. "If we played Saturday, maybe. We'll see."

Winnipeg has a bye in the final week of the regular season and is still battling with the Stamps and Saskatchewan (11-5) for a home playoff date. Winnipeg and Calgary's season series is tied 1-1.

"He's learned the playbook quickly," O'Shea said of Collaros. "He's a pro. He's been on a team that's won a Grey Cup and led another team to a Grey Cup so he's been through this time of year lots of times before. He's a good quarterback."

Calgary head coach Dave Dickenson, a former quarterback whose multiple concussions forced him to retire in 2009, said he can relate to what Collaros may be going through.

"When I was coming off injuries, sometimes I'd say like, it's not like you're looking forward to the first hit but you also want to get hit and you want to feel good after you get hit," Dickenson said.

"Whether he admits it or not, I'm sure that's going through his brain."

Bombers left tackle Stanley Bryant will be covering Collaros's blind side and said he hasn't thought about the pivot's history of concussions.

"Upfront we're one of the top-tier offensive lines in the league," Bryant said. "I think we do a great job of protecting our quarterback and also our running back."

Winnipeg's offence has allowed 34 quarterback sacks, ranked fourth in the league. Calgary's defence is fifth in sacks with 34, but it's missing injured team sack leader Cordarro Law, who has 10 of those.

Bryant and running back Andrew Harris both described the six-foot, 219-pound Collaros as calm and collected in the huddle.

"He's got a great frame on him and he runs the ball well out of the pocket and can scramble well," Harris said. "He makes all those great big throws so I'm definitely excited to see what he can do on the field."

Calgary quarterback Bo Levi Mitchell, who's had a concussion-free career, said he had dinner with Collaros and their mutual agent after last weekend's game.

"He's a guy you definitely respect, a future coach kind of guy..." Mitchell said of Collaros. "I'm excited to see the guy get back on the field because he deserves it.

"He's had some very, very unfortunate things go on over the last couple of years. Hopefully, he gets out there and plays well, but doesn't play too well."

CALGARY (11-5) AT WINNIPEG (10-7)

Friday, IG Field

MILESTONE ON THE HORIZON: Bombers running back Andrew Harris leads the league in rushing with 1,316 yards. He sits ninth on the CFL's all-time list and needs 26 yards to reach the 9,000-yard milestone.

CRITICAL DOWNS: In Calgary's win last week, the Stampeders converted on 65 per cent of their second downs compared to Winnipeg's 33 per cent.

HOME TURF: The Bombers can't finish first in the West Division, but can snag a home playoff date if they beat Calgary, the Stamps lose next week to B.C. and Saskatchewan ends its season with back-to-back losses to Edmonton.

This report by The Canadian Press was first published Oct. 24, 2019.