San Francisco 49ers running back Raheem Mostert was hoping his breakout 2019 campaign would result in a pay raise.

But after months of unsuccessful negotiating, Mostert officially asked for a trade on Wednesday afternoon, per his agent Brad Tessler.

The 28-year-old was the most effective back in the Niners' backfield last season, rushing for 772 yards and eight touchdowns on 5.6 yards per carry. Mostert also averaged nearly 13 yards per reception.

It remains to be seen whether the 49ers will opt to trade Mostert or give him what he is seeking financially. They have a crowded running back room with Jerick McKinnon returning to action, but Mostert had easily the best success rate last season.

Any number of teams could show interest in Mostert, depending on the cost. Mostert's cap hit is just over $3 million for 2020, per Spotrac, though any team acquiring his services would likely seek some sort of extension and he, a raise.

In any case, here are the five best trade destinations for Mostert should the 49ers decide to move on from the formerly undrafted back.

5. Chicago Bears

Bears fans still have reason to be optimistic about their running backs.

David Montgomery averaged just 3.7 yards per carry in his rookie season, but he also ranked seventh in broken tackles (28) and was an exceptional route-runner and pass-blocker.

The Bears are hoping for a healthier and improved offensive line, which would bode well for a hard-nosed runner like Montgomery.

Tarik Cohen was also a disappointment last season, averaging just 5.8 yards per reception and totaling 669 yards from scrimmage one year after going for nearly 1,200 yards. However, he is still capable of breaking a big play and can be an effective receiver in the slot.

Perhaps the Bears would feel more comfortable adding Mostert as a means of competition. He would offer a change of pace from Montgomery and Cohen, something which would surely be valued by head coach Matt Nagy.

4. Philadelphia Eagles

Philly's incentive is slightly different from Chicago's in any trade for Mostert.

The Eagles have a clear feature back for the future in Miles Sanders. The former Penn State standout had over 1,300 yards from scrimmage, averaging 4.6 yards per carry and over 10 yards per reception.

But the Eagles also had an apparent desire to add a veteran back after Jordan Howard walked in free agency. They have yet to make any addition of consequence.

It is true Philly will want to get more usage out of Sanders. But, like Mostert, Sanders also excels in special teams. Trading for Mostert would give the Eagles two backs with complementary skill sets.

Plus, Doug Pederson is one of the most creative play-callers in the game. He could certainly find a way to incorporate both players in multiple-back sets, perhaps even choosing to send Sanders out wide or in the slot.

3. Los Angeles Chargers

The Chargers essentially opted for Austin Ekeler over Melvin Gordon by singing Ekeler to an extension this offseason. Like the Eagles, they also lack depth.

But whereas Sanders is likely to grow into his own as a pure runner, Ekeler is even better when he has the opportunity to work the slot or run wheel routes against slower coverage matchups.

Trading for Mostert would not only give the Chargers more depth, but also allow Anthony Lynn to continue using Ekeler as a receiver.

Mostert might also be the perfect kind of back for a run-pass option offense, something L.A. figures to run extensively with Tyrod Taylor under center.

2. Houston Texans

Texans fans would probably prefer Bill O'Brien to stop making trades at this stage of the offseason.

Simultaneously, however, are the Texans content with David Johnson as the starter?

Johnson missed all but one game in 2017, and missed three more last season while also being unseated as the starter. Even though he was healthy in 2018, Johnson averaged just 3.6 yards per carry and a career-low 8.9 yards per reception.

Duke Johnson had a strong 2019, but, like Ekeler, he is at his best when split out wide. The Texans would likely prefer a different feature back so they can get creative with Duke as a pass-catcher, particularly given some of the questions at receiver following the DeAndre Hopkins trade.

Of course, there is also the notion Mostert might simply be a better option than David Johnson at this stage of his career.

1. Jacksonville Jaguars

Leonard Fournette rushed for over 1,100 yards and totaled nearly 1,700 yards from scrimmage last year. He is a quality back.

But Fournette is also likely headed out of town. Fournette was the subject of trade rumors last year, and the Jags declined to pick up his fifth-year option for 2021, making him a free agent at the end of this year.

It seems Jacksonville is intent on moving in a different direction. Given the team is in a rebuild, why not seek a trade for Mostert and give him a chance to shine?

The Jags are committed to Gardner Minshew as the starting quarterback. They would probably feel more confident in his progression if they could establish the running game from the jump.

Mostert would not only be able to pound the pigskin, but is also more explosive than Fournette in the open field.

Particularly if the Niners decide to sell somewhat low on Mostert, the Jags would be wise to swoop in and make deal.