In a perfect world, Jerick McKinnon would somehow make a miraculous recovery from his latest setback and be ready to play in a couple of weeks when the San Francisco 49ers open the regular season in Tampa, Florida.

That is unlikely.

As far as the depth chart goes, the 49ers can deal with McKinnon's injury. The team still has Tevin Coleman, Matt Breida, Raheem Mostert, and others. McKinnon represented a potential embarrassment of riches at the position, had he become healthy.

McKinnon isn't healthy, and it doesn't sound like that will change anytime soon. Assuming things don't take a turn for the better, general manager John Lynch and head coach Kyle Shanahan will have a decision to make — one that could impact another player on the roster.

McKinnon has suffered three setbacks in his attempted return from a torn ACL sustained on September 1, 2018. The first landed the running back on the Active/Physically Unable to Perform (PUP) list to start training camp. The second was following two practices after being activated off the PUP list in early August. Then the latest came after one practice this week.

"We [were easing him back in] a month ago, and we got to that step (of being close to a return), and he kind of regressed," Lynch said Wednesday on KNBR. "And I would say [Tuesday], we had a similar situation. So we're trying to get to really what's the root cause of the problems that he's having.

"Just because he's kind of working through this, we're working it, I'm going to kind of leave it at that, but [Tuesday] was not encouraging from that standpoint. What that means, we're not sure yet, and we're working hard to find that out."

Money-wise, there is little impact from keeping McKinnon on the roster. His salary became fully guaranteed on April 1. If the 49ers wanted to easily part ways with the running back and his salary, they would have done so before that deadline. There isn't much benefit to releasing McKinnon this season. He'll be paid either way. And an injured running back has no trade value.

With money not being much of a factor, the team needs to decide what to do with McKinnon's roster spot.

Assuming McKinnon is sidelined for more than eight weeks, San Francisco could place him on injured reserve before Saturday's roster cutdown deadline. That would end McKinnon's season for the second-straight year, and the team could delay any long-term decision until 2020. The problem is that the 49ers would need to have a clearer picture of the recovery time for McKinnon or at least be confident that he wouldn't be needed nor available this season. A quick flashback to the injuries at the position last season, including McKinnon's, might give them pause if there is a chance the running back can contribute by mid-season.

Then you have the short-term injured reserve option. McKinnon could be one of two players brought back to practice after Week 6 and activated to play after Week 8.

There is one problem with that scenario, though. For McKinnon to be eligible to return, he would need first to be part of Saturday's 53-man roster. The running back eating up a roster spot would mean the 49ers would have to waive a player they might otherwise consider keeping. That creates a problematic situation for Lynch and Shanahan. Should they waive a player and expose him to the 31 other NFL teams just to place McKinnon on injured reserve in hopes of bringing that player back? It's a risky gamble.

The 49ers have come a long way since Shanahan envisioned McKinnon as a featured component within his offense. The team has evolved and has a lot more depth. There is no doubt Shanahan would love to have a healthy McKinnon at his disposal. Again, it would be an embarrassment of riches at the running back position. It doesn't look like that will happen soon.

We'll likely know more about McKinnon's status by Saturday at the latest.