But when Mostert returned to the site where he began a journeyman NFL career on Sunday, he was the one person in M&T Bank Stadium who clearly remembered it. And he made it a point to remind the Ravens that a little-known, special-teams player they let go in 2015 has become a legitimate weapon in more ways than one for the 49ers.
"I didn't really have a good experience when I was here," Mostert said. "But I made the most out of my opportunities when I was. I wasn't holding on to a grudge, but I really did want to show the organization what they missed out on, and it worked to my benefit."
According to Mostert, he had been with the Ravens for about six games in 2015, playing exclusively on special teams, when he was told he was going to be cut. Apparently, he got bad information and wasn't cut then, but Baltimore let him go the following week without seeing what he could do with the ball in his hands.
Upon making his return to Charm City on Sunday, Mostert figured into the game plan, as Matt Breida continued to recover from an ankle injury. But nobody, including Mostert himself, knew what was in store.
After the Niners' run game got off to a slow start, Mostert stepped in for Tevin Coleman. On first-and-10 with 9:22 left in the second quarter, Mostert burst off the right side, darted down the sideline and made safety Earl Thomas whiff on his way to a 40-yard touchdown. It was Mostert's fourth career rushing touchdown and third that has gone for 40 or more yards, all of which have come since the start of the 2018 season.
"Once he got in there, we saw a few of the runs he made, he was pressing it very well, and we just stuck with the hot hand after that," coach Kyle Shanahan said.
Indeed, nobody's hand was hotter than Mostert's, as the Niners searched for offensive production amid the steady rain that fell throughout their 20-17 loss to the Ravens. On a soggy field that most players described as "mushy," Mostert seemed plenty sure of his footing as he repeatedly attacked the edges of Baltimore's defense on the Niners' preferred outside zone run designs.
With tight ends such as George Kittle, fullback Kyle Juszczyk, the receivers and the offensive line opening holes against the Ravens' aggressive blitzing approach, Mostert was the perfect candidate to take advantage with a burst quarterback Jimmy Garoppolo said is "like no one I've ever seen."
"Raheem is the best at just being decisive and hitting things fast," Juszczyk said. "And that plays out perfectly in a game like this, where people might be a little indecisive, not sure of their footing, and that's going to play right into his advantage, where he's going to crease it every time. He killed it today."
In a big game against the league's hottest team, Mostert -- who remains one of the league's best special-teams players -- was the latest in a long line of Niners called upon to play a bigger role than expected and who made the most of the opportunity.
Mostert finished the day with career highs in yards (146) and carries (19), an average of 7.7 yards per attempt. He became the third Niners running back this season (along with Breida and Coleman) to have a 100-yard game, and his 146 yards were the most on the ground by a Niner since Carlos Hyde had 193 against the New York Jets on Dec. 11, 2016. It was also Mostert's first time rushing for a touchdown in back-to-back games.
With another big game awaiting next week in New Orleans and likely more to come, having another dangerous offensive weapon should only benefit a team that continues to find production where it's least expected.
"This whole team, we ask so much of so many guys," Kittle said. "It doesn’t matter the position, what they’re doing -- special teams, defense, offense -- they step in and make a play when your name is called. You give guys an opportunity to make the play, and Raheem did that today, and he definitely provided us a big spark."