The 49ers will place Jerick McKinnon on injured reserve, according to Ian Rapoport of NFL.com (on Twitter). At this moment, it’s unclear as to whether McKinnon could conceivably return during the season as an IR-DTR player.
San Francisco will, in fact, be without McKinnon for a second straight season. The 49ers are placing the running back on season-ending IR, Matt Maiocco of NBC Sports Bay Area tweets. 
McKinnon’s surgically-repaired knee flared up in recent days, setting him back significantly. It’s an unfortunate chain of events for the former Vikings rusher, who was unable to suit up for the Niners last year to break in his lucrative free agent contract.
The 49ers inked McKinnon to a four-year $30MM contract in 2018, but a torn ACL wiped out his first would-be season in SF. It was a huge disappointment for the team and player alike – McKinnon flashed serious potential in Minnesota and many expected him to bust out big plays in the 49ers’ offense.
In 2017, his final year with the Vikes, McKinnon enjoyed career highs in receptions (51) and receiving yards (421). With capable hands and the athleticism to break out of early tackles, McKinnon offered the ability to go for long-distance runs and serve as a security blanket for Jimmy Garoppolo. Both players were knocked out by injuries in 2018, and McKinnon’s sideline stint will extend into at least part of 2019.
Should have stayed with the Vikings,
Now 2 PRIME years of his career flushed down the toilet!
Plus he now has a gimpy knee….
The reward for GREED !!
What a dumb comment! The guy had a chance to become a STARTER in the NFL and bad luck cost him a season and a half…but you’re saying he should have re-signed with the Vikings for probably 50% of the money to be a backup? I’ll give you the benefit of the doubt here and assume you were using sarcasm…one could only hope!
So you’re insinuating that he doesn’t blow his knee out if he stays with the Vikings? Anything can happen, don’t be ignorant.
So how much is guaranteed and when can he be cut? Not to be harsh, but it’s probably time to cut your losses on this one.
We already have someone who can do all the things he can do and probably better..Brieda! Never understood signing him and I feel terrible but I really hate that we have spent all that money on someone who won’t end up playing for us. My guess is he gets released which should happen or he will retire because he won’t ever be the same. I say since he already got his money and it would be the nice thing to do let him rehab with the team but cut him in the offseason because like I said, we have a back like him and this guy will never be the same.
I believe his first two years were fully guaranteed, so cutting him now does nothing for SF. I loved the signing when they made it. A combination of McKinnon & Brenda would have been nasty last year with a healthy Jimmy G.
When SF signed Tevin Coleman this off-season, the writing was on the wall that McKinnon would not be ready for the season. Hopefully he can return mid way through the season, showcase his talents, and find a good landing spot next season (once his guaranteed money runs out). He is really talented and would have loved to see what he could do as a featured RB.
Football is a tough profession!