In April, the 49ers selected Kansas State safety Marques Sigle in the fifth round of the draft. The team also has Ji'Ayir Brown returning, but lost veteran Talanoa Hufanga to free agency.
The injury is a blow to the 49ers' defense. Fans were eager to watch the hard-hitting safety build on his rookie year and take another step forward in 2025.
NFL.com's Gennaro Filice recently named Mustapha the 49ers' most underappreciated player. Highlighting one such player for each NFL team, Filice emphasized the importance of low-cost, high-impact young talent for the 49ers now that quarterback Brock Purdy is the highest-paid player in franchise history.
"The 49ers found one of those in the fourth round of last year's draft, with Mustapha immediately making his presence felt as a violent playmaker," Filice wrote.
Unfortunately, Mustapha's timeline for a return is uncertain. His impact may not come until later in the season. After a 2024 season marred by injuries, the 49ers now face the challenge of starting 2025 without one of their most promising young defenders.
"He still gets shine here, though, because I self-consciously feel like I personally underappreciated the safety by completely omitting him from last season's rookie rankings," Filice added. "This dude's punishing play style is too endearing to go unrecognized!"
Mustapha ended his rookie campaign with 72 tackles (including two for loss), one interception, and five passes defensed.
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