The 49ers have to make a tough decision about Dre Greenlaw this offseason.

An emotional decision would be to re-sign him to a lucrative multi-year extension. Greenlaw has been the heart of the 49ers defense for years — they are decidedly soft without him. And they have been unable to replace his impact while he has been out.

Both Nick Bosa and Fred Warner have said they want the front office to re-sign Greenlaw this offseason essentially no matter what. Doing so would be a sentimental mistake.

Greenlaw was a great player before he tore his Achilles tendon in the Super Bowl last year. Since then, he hasn’t proven he can play a full game without re-injuring himself. That’s the hard truth of the matter. He made his season debut against the Rams and couldn’t play in the second half. Then he played the following week against the Dolphins and couldn’t play after the first drive. Then he missed the rest of the season.

If the 49ers are feeling generous, they can offer Greenlaw a modest one-year deal that would allow him to prove that he can stay healthy for an entire season before cashing in on a contract extension. They should not offer him anything more than a one-year deal. They can’t afford to commit themselves long-term to injured players. They already did that last season with Christian McCaffrey and Trent Williams.

The 49ers need to find the next Greenlaw in the upcoming draft.