NFL free agency: How Tevin Coleman addition shakes up 49ers running back depth chart

The San Francisco 49ers made another NFL free agency splash, grabbing former Atlanta Falcons running back Tevin Coleman and signing him to a two-year deal. But what does that mean for an already-crowded crop of Niners tailbacks in 2019?

It might be one of the most underrated pickups in free agency so far -- the San Francisco 49ers bringing aboard versatile running back Tevin Coleman and signing him to a two-year deal worth $10 million, as ESPN's Adam Schefter reported on Wednesday.

Coleman thrived under head coach Kyle Shanahan, who oversaw the 6-foot-1, 210 pounder's efforts with the Atlanta Falcons back in 2015 and 2016. Splitting time with the Falcons' No. 1 tailback, Devonta Freeman, Coleman managed a total of 3,350 all-purpose yards during his four-year Atlanta tenure.

Considering how much Shanahan likes speed from his skill players, it's not hard to see how well Coleman will fit into the Niners offense:

With this addition, however, there are some problems and question marks. Running back wasn't exactly considered a top need for San Francisco this offseason. The 49ers were already pegged to get last year's prime free-agent investment, Jerick McKinnon, back from a season-long ACL injury. Additionally, running back Matt Breida will return from a season in which he averaged 5.3 yards per rush attempt -- good for fourth best among all qualifying rushers in the league last year.

Signing Coleman points to one of a number of different scenarios, and each one of them has merit. It's possible the Niners aren't fully convinced McKinnon will be fully recovered and ready for the start of the regular season. Even if he is, it's likely San Francisco will want to limit his workload to a large extent, particularly early on. Breida, while seeing 14 games last year, was regularly on the team's injury report and isn't considered a workhorse running back.

That boils down to two questions for Shanahan and Co. Are the Niners planning on keeping all three in regular roles? Or is a player, such as McKinnon, in danger of being let go?

Let's go with the latter first. It seems silly the 49ers would part ways with McKinnon, who has yet to take a regular-season snap with the 49ers, after signing his four-year, $30 million contract in 2018. But as ESPN's Dan Graziano pointed out, McKinnon has zero left in fully guaranteed money, and his 2019 guarantees won't kick into effect until April 1. That leaves the 49ers with a little leeway to make what would be a crucial decision, and McKinnon's relatively team-friendly deal still affords the Niners to make this decision even later, should they choose.

Also in the mix here is running back Raheem Mostert, who saw an increase in offensive production before breaking his forearm in Week 9, but is also seen as a core special teamer. Mostert's fit, as argued by NBC Sports Bay Area's Matt Maiocco, all but ensures him a spot on the 46-man active roster on game day, leaving only two active spots open between McKinnon, Breida and Coleman:

One could assume, then, McKinnon's roster spot just got pushed onto the bubble this offseason. Yet there's a counter to Maiocco's argument about having only three runners on San Francisco's game-day roster.

The easy out would be suggesting Mostert won't make the cut, which is entirely possible. But it's also just as possible the 49ers trim their wide receiver or tight end depth chart a spot, especially considering both Coleman and McKinnon can double as pass catchers in the slot at the line of scrimmage. We are talking about Shanahan's play calling here, by the way.

Additionally, Schefter even suggested this running back trio is a dispersal of weaponry few teams can match, yet many try to achieve:

On the positive side of all this, though, is Shanahan gets a weapon he used with great success in previous years, which should make an already-solid 49ers rushing attack even more potent.

Regardless of McKinnon's future, which is still far from decided.