The 49ers had been gradually working Mustapha into the lineup, with his previous high of 31 snaps coming in Week 2 when he shared duties with George Odum. However, the coaching staff had enough confidence to leave him in for the entirety of Sunday's game.
"Yeah, we thought he was ready for it," head coach Kyle Shanahan said following the 30-13 win. "When him and G.O. (Odum) were going, we started rotating him a little, I think, the second week. He's been doing awesome in practice. We started to mix him in there in game two."
In Week 3 against the Los Angeles Rams, Mustapha only saw five snaps, as Hufanga returned from a torn ACL and played 53 snaps. This limited the rookie's opportunities, but Sunday presented a new chance for him to prove himself.
"But when we found out Huf couldn't play today, we knew he (Mustapha) was the next man up," Shanahan explained.
Linebacker Fred Warner praised the young safety, commenting on how well Mustapha has integrated into the defensive unit.
"I thought he did great," Warner said. "He had that opportunity to have an interception late in the game—[you've] got to bring those in. But other than that, I love the way that Malik plays the game. I mean, hair on fire, no hesitation.
"You see him just flashing all the time with the way that he sprints to the football. I love the way that he plays the game. He's only going to continue to get better."
No concerns about Hufanga
Despite Hufanga's absence, the 49ers aren't overly concerned about the All-Pro safety's ankle injury. He suffered the setback in practice last week and was seen testing the ankle pre-game to determine if he could play. He was listed as questionable entering the contest and, ultimately, was one of the 49ers' five inactive players.
Shanahan addressed whether Hufanga was close to playing and if there are concerns that the latest injury might become a lingering issue.
"I don't think so," Shanahan reassured reporters. "We thought he would play today, but we knew it would be a game-time decision. He got here early, he worked out, and he didn't feel like he could go, and I'm really glad that he didn't."
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