Let me start off by saying, I don't think Shane Bieber is a top starter anymore and he does not fit the profile of the kind of starter I think they need to acquire to take a big step forward. With that being said, Bieber would still be a good addition to the Cardinals rotation, assuming the price point is low, and would at least help them look more like a high-80s win team in 2024.
One of my worries with a Bieber deal is I think the Guardians would want teams to pay like he's still a big name, but in reality, he's regressed from that. He could regain that form in the next few years, and it sounds like he's trying to get his velocity back, but it's not worth paying for that chance if the Guardians want that price to reflect that potential.
If the Guardians recognize that he has diminished a bit as a pitcher and had a 3.80 ERA in just 21 starts last year due to injury, then the Cardinals could have a real conversation here.
The most I'd be willing to consider if I'm the Cardinals in a Bieber deal is someone like Alec Burleson or Dylan Carlson, but anything more than that and I'm totally out. I also don't think I go for Bieber if it takes me out of the market for other names on this list, but I don't hate it if the price point is low and the other options just aren't there.
Right now, Bieber probably projects to be more like a good number-three starter than a front-line guy, but the potential is there to be more than that. Two years ago, when his stuff was already diminishing some, Bieber finished 7th in Cy Young voting, so he's at least shown the ability to be very effective, even without incredible stuff.
The main reason I included him on this list is it feels like something the Cardinals may consider, even if I'm not a big fan of it. It's true that it would upgrade their rotation, but it feels like a small step in the right direction, rather than the big step they have an opportunity to take.