While many San Francisco 49ers fans jumped on the Nick Mullens bandwagon following his fantastic NFL debut against the Oakland Raiders, the 49ers did suffer a setback during the game.
Although Mullens was able to guide the 49ers to a 34-3 victory on Thursday night against the Raiders, they were also able to get things moving on the ground too to control the game in their favour.
Due to injuries to many of their running backs, San Francisco split the carries across their backfield throughout the night between Matt Breida, Alfred Morris, and Raheem Mostert.
In total, the 49ers running game was able to produce 143 rushing yards and a touchdown off 32 carries between them, with Mostert getting most of the yardage and the only score on the ground on the night.
Mostert had 86 yards and a touchdown from seven carries on the night, with his longest play being a 52-yard score, but he was forced to leave the game early in the third quarter due to injury.
It was a nasty and gruesome injury too. Mostert was tripped on a rushing play and landed with his body weight on his right arm. It bent his arm in a way which it shouldn't be bent, so viewer discretion is advised in the video below.
It was later confirmed that the running back had suffered a fractured arm and although the 49ers are yet to confirm it, he is likely out for the rest of the season.
It's such a shame for Mostert as the 26-year-old was taking advantage of the 49ers' current backfield situation which has seen Breida play despite having an ankle injury for several weeks.
As a result of Mostert's injury, Breida and Morris will likely share backfield duties when San Francisco plays against the New York Giants in that Week 10 game.
Mostert finishes his 2018 season with 261 rushing yards and a touchdown off 32 carries.