Entering their Week 5 matchup with the Los Angeles Rams, the San Francisco 49ers had a big disadvantage as they were without their $265 million starting quarterback, Brock Purdy. Even so, backup quarterback Mac Jones stepped into the role as the starter and played incredibly well.
In fact, Jones played so well, that fans and analysts alike were calling for him to be the new starter for the 49ers over Purdy.
Unfortunately, however, Jones went down in the red zone after a tough hit, grabbing his knee. With the 49ers potentially going down to their third-string emergency quarterback, they would have to finish the game with Adrian Martinez. Thankfully, Jones did return to the game for the team’s next possession and even ran a QB sneak, showing his incredible toughness.
A Look at Adrian Martinez, the 49ers’ QB3
Martinez has yet to play a snap in the NFL, but he was a standout player in the UFL last season for the Birmingham Stallions.
Not only was he a star, but he won the league’s MVP award and led his team to the championship last season.
Mac Jones full injury 🙏
This sucks…pic.twitter.com/y4QlefmST2 https://t.co/7z2Mb0274u
— Dov Kleiman (@NFL_DovKleiman) October 3, 2025
Prior to joining the Stallions, Martinez went undrafted, and though he signed with the Detroit Lions as an undrafted free agent in 2023. He was unable to find a place for himself in the NFL, which eventually led him to signing with Birmingham in the UFL.
Martinez signed with the 49ers’ practice squad in August after he was waived by the New York Jets. He was elevated to San Francisco’s main roster before their ‘Thursday Night Football’ matchup with the Rams. Had they not signed Martinez, the next man up would’ve been star running back Christian McCaffery, who was initially listed as the team’s backup quarterback on the depth chart.
🚨 BREAKING: Christian McCaffrey is listed on the 49ers depth chart as the RB1, QB2, WR1, and TE1 ahead of tonight’s TNF matchup vs. the Rams pic.twitter.com/DFrUrPJGWi
— PrizePicks (@PrizePicks) October 2, 2025
In 2021, Martinez totalled 27 touchdowns for the Nebraska Cornhuskers, with 2863 passing yards and over 500 rushing yards. His 86.6 PFSN College QBi score was the third-best of that season and ranks 22nd out of all college football quarterbacks since 2019.
Although he has yet to see the field despite Jones’ injury, Martinez will have to be prepared to make his debut at some point this season if injuries continue to plague the 49ers’ quarterback room.
