SANTA CLARA, Calif. — For the past two seasons, Jordan Mason has looked like a starting running back, but until Monday night, he was unable to play that role.
The wait may have been longer than Mason wanted and came under less than ideal circumstances – he was replacing the injured Christian McCaffrey – but it was clear from the season opener that Mason was more than ready for the task, as he and the Niners crushed the New York Jets on the ground, winning 32-19.
“I’ve been working towards this moment all training camp and I’m blessed to be able to play and show it today,” Mason said.
When Mason finished, he had set a career high with 28 carries for 147 yards. He scored on a running score and caught a pass for another 5 yards. After the win, some wondered when the Niners knew McCaffrey would be out and Mason would step in.
In an on-field interview with ESPN’s Lisa Salters, Mason said he learned he was eligible to start “maybe Friday night.” Coach Kyle Shanahan said no decision was made Friday and nothing will be decided until Monday.
Regardless, Mason’s start came as a surprise after McCaffrey was declared unavailable for action 90 minutes before Monday night’s game at Levi’s Stadium due to lingering calf and Achilles tendon injuries. During the week, McCaffrey participated in all four of the Niners’ practices on a limited basis and was officially listed as questionable on Saturday’s final injury report.
Despite all of that, McCaffrey was expected to be ready to play. McCaffrey said Friday afternoon he had no doubts he would play against the Jets and expressed hope he could handle his usual heavy workload.
After the game, Shanahan said it was “a little too much” for McCaffrey to play today, noting that San Francisco “thought it would be wise to leave him out.” Shanahan added that McCaffrey had not suffered any setbacks in practice.
“All week it was in and out of the way,” Shanahan said. “He was able to practice all week, but it always bothered him a little bit. Sometimes it goes away. Sometimes it comes back. Today it bothered him a little too much and he didn’t feel good about it.”
McCaffrey’s injury and Elijah Mitchell’s season-ending hamstring injury in training camp opened the door for Mason to move up the rankings, an opportunity he quickly seized with a strong training camp in which he likely would have passed Mitchell anyway.
Mason’s performance in training camp gave the Niners confidence that he was ready to step in and perform, even though he hadn’t had more than 11 carries, 69 yards or 27 offensive snaps in any NFL game before Monday night.
His 28 carries were the most in a regular-season game by a Niner since Shanahan took over in 2017 and the most in a 49ers season opener in franchise history. His 147 yards were the fourth-most rushing yards in a season opener by an undrafted player all-time and the second-most by an undrafted player on “Monday Night Football.”
This performance was no surprise to those in the Niners locker room, who have seen Mason develop from a 2022 undrafted free agent out of Georgia Tech to a player who averaged 5.6 yards per carry in his last 33 NFL games.
“As far back as I can remember, he looked like that every time he touched the ball,” left tackle Trent Williams said. “That’s what he looked like tonight. … I’m sure he’s matured over the last few years, but I couldn’t see a glaring gap and he’s matured. He came in pretty mature and was always ready for his opportunity. Even as a third or fourth back, he was always ready and he came in and finished a lot of plays for us and ran hard and he earned everybody’s respect.”
Many of Mason’s teammates, including receiver Deebo Samuel Sr. and fullback Kyle Juszczyk, said they learned Friday that Mason would start for McCaffrey. Shanahan said he and other coaches told Mason throughout the week that he might have a bigger role and to prepare for it, but he didn’t tell him until Monday afternoon that he would definitely start.
“We found out he wasn’t playing today and we don’t know how he’s going to feel tomorrow or the day after,” Shanahan said. “I thought he was going to play all week, until today.”
Depending on how the rest of this week goes for McCaffrey, the mystery may not be so great after all as the Niners prepare to play against the Minnesota Vikings on Sunday. San Francisco’s next two games will be on artificial turf, which could prevent McCaffrey from returning immediately.
Shanahan said it was too early to comment because McCaffrey would be under surveillance again later this week.
“I ask the player how he feels,” Shanahan said. “If he feels good and he’s ready to go, then he’s ready. If he says I feel good on grass but not on artificial turf, then that’s usually a way of saying you don’t really feel good. We’ll see how he feels tomorrow. We’ll see how he feels the next day and how he feels on Sunday.”
And if the Niners need to go back to Mason, they won’t hesitate given his performance on Monday night.
“I thought he ran like he always does,” Shanahan said. “When you give him the ball, he breaks tackles and usually gets more than we block. When we had the good lanes, he always hit them and we got a lot, but JP was great today.”
