Now let's do Matthew Stafford, the one who actually is available.
Stafford and the Lions agreed to "mutually part ways" on Saturday. Meaning the Lions want to rebuild and Stafford doesn't, so they've agreed to send him out of town. And the 49ers absolutely should pursue him.
Typically, teams don't trade franchise quarterbacks to teams who play in the same conference. But as I wrote above, the Lions are rebuilding -- that's why they gave new head coach Dan Campbell a six-year deal. They expect to lose. They're not worried about having to compete against Stafford in an NFC Championship because the Lions won't play in one any time soon.
Which means the Lions will trade Stafford to the highest bidder, and that could be the 49ers. They could send Detroit the 12th pick in the upcoming draft.
But the the Broncos could send Detroit the ninth pick for Stafford, because they need a quarterback. And the Panthers could send Detroit the eighth pick, because they need a quarterback, too.
The 49ers could have quite a bit of competition for Stafford.
They might have to trade a first-round pick and a second-round pick to Detroit for Stafford. Or two first-round picks. Or two first rounders and a third. Or two first rounders and a player. Who knows? Funny things happen during bidding wars.
The 49ers should trade no more than a first-round pick for Stafford. And even that first rounder would be rich for a quarterback who will turn 33 in February and never has won a playoff game in the NFL.
I expect the 49ers will let some other team overbid for Stafford's services.