Anthony Calvillo has a confirmed concussion, which raises questions about his future

How do you replace professional football's all-time leading passer? The Montreal Alouettes are about to find out, as they announced Tuesday that quarterback Anthony Calvillo has been diagnosed with a concussion from a hit he took in Saturday's loss to Saskatchewan. Calvillo left that game after a second-quarter hit from the Riders' Ricky Foley and didn't return, and there was plenty of talk that he may have suffered a concussion, but the team didn't make it official until Tuesday, announcing on Twitter that Calvillo won't play Thursday against B.C.:

While Calvillo's absence for a game is certainly concerning for Montreal, it's the long-term implications that may be really problematic here. We're already seeing some suggestions that perhaps he should hang up his cleats for good, including this one from Vicki Hall of The Calgary Herald:

A lot of that's disputable (the end doesn't seem all that clear from this standpoint, especially considering how Calvillo has overcome ridiculous levels of adversity in the past, and Montreal's problems this year are about far more than just his play), but it's interesting to see this even discussed. It's also not out of the question that Calvillo could elect to hang his cleats up. We've seen time and time again the horrific effects can have on players, and some former players, like TSN analyst Matt Dunigan, have spoken about how concussions from their playing days still bother them today. Concussions can have drastically different effects on different people, too: some players feel back to normal a week or two after, while for some, like Calvillo's teammate Shea Emry, a concussion can mess up a whole year or more. If this proves to be a long-lasting one, that might just persuade Calvillo to quit.

We know from watching Calvillo over the last 20 years that he doesn't give in easily, though, and his decision to continue playing in 2010 (winning a Grey Cup along the way) before undergoing surgery to remove his thyroid and the cancerous cells inside it says a lot about his determination to overcome obstacles. That's an outcome the Alouettes should be hoping for, too. Yes, their 2-5 start is far from ideal, but there's still a lot of time to turn things around, and plenty of teams have gone from bad starts to Grey Cup champions (including the last two teams to lift that trophy). Montreal can't be written off yet, especially if their star QB can return and find his typical level of form.

This team's highly unlikely to get anywhere near there without Calvillo, though. Backup Josh Neiswander is in his third season with the team, but had never seen regular-season CFL action until Saturday, and that showed: he completed just 12 of 30 passes for 147 yards with two interceptions. While Neiswander, third-stringer Tanner Marsh and newcomer Troy Smith are all intriguing options and potential long-term replacements for Calvillo, there simply isn't any experienced QB depth in Montreal, and that bodes poorly for the Alouettes' chances if Calvillo's out for a while, especially considering their extensive litany of other injuries. It's nice to see a team being cautious with a concussed player, as that hasn't always been the case in this league, and Calvillo certainly shouldn't return until he's cleared by doctors. Depending on how his recovery goes, maybe that never happens and maybe this is in fact how it ends. Given Calvillo's persistence and perseverance, though, the bet here is on him returning to the Montreal lineup later this season. Alouettes' fans should be hoping that bet's right.