Calvin is such a beast, didn't some ppl say the Lions should trade him? Lol smh
The reason for the trade talks were because, at the time, the Lions had absolutely no talent around him, and with a No1 overall and two No2 overall draft picks pre-rookie salary cap, the money structure of the team is pretty well boned. Trading Calvin at a time when it looked like he wouldn't do any good for us anyway would ease the team's salary cap woes and allow them to build an actual team.
Technically if Stafford's good enough to warrant being a number 1 pick overall QB, he shouldn't need someone as ridiculously good as Calvin to lead a winning team...but it sure helps to have him now.
EDIT: As you can see, we're happy to have kept Calvin here after all.