Christian McCaffrey has a mild calf strain and Dalvin Cook just became a free agent — should the 49ers sign him?

Ordinarily, the answer would be yes, because the 49ers have plenty of cap space and a team can’t have too many good players. And Cook went to four straight Pro Bowls from 2019 to 2022 when he was with the Vikings. He was a premier running back.

But now he’s 28, and he was awful this season with the Jets — that’s why he’s a free agent now. He’s averaging 3.2 yards per carry, a career low. And he was unhappy being the backup in New York, because he’s accustomed to starting. So he and the Jets mutually agreed to part ways.

Which means Cook would be a horrible fit with the 49ers, because he would have to be a backup. Frankly, he would be the worst running back on the team, because McCaffrey, Elijah Mitchell and Jordan Mason all are better than Cook at this point of his career. He’s cooked — no pun intended. Stick a fork in him.

Cook’s rapid decline is a good reminder for the 49ers that running backs age rapidly. Just last season, he rushed for 1,173 yards and 8 touchdowns. He was excellent. Now he’s unplayable.

Which brings us to McCaffrey, the best running back in the league currently. He will turn 28 in June. I’m not saying he’ll fall off a cliff like Cook did, but you never know with running backs.

The 49ers need to cherish the time they have with McCaffrey, because it all could end soon.