The 2025 NFL season has gotten off to a rough start for the San Francisco 49ers, who have endured a flurry of injuries to important playmakers all over the roster. One of the bigger names is quarterback Brock Purdy, who has been out with a toe injury.
The 49ers turned to Mac Jones, who has been surprisingly solid in Purdy’s stead, but after taking a couple of big hits on Thursday Night Football against the Los Angeles Rams, he is noticeably hobbled. Who is the next man on the 49ers depth chart if he has to sit?
Who Is Behind Mac Jones on the San Francisco 49ers Depth Chart?
The 49ers were already on plan B with Jones starting under center after Purdy suffered a setback against the Jacksonville Jaguars in Week 4. For now, it seems they have avoided going to plan C, former Birmingham Stallion QB Adrian Martinez of the United Football League.
As the 49ers drove towards the end zone during their opening drive of the second half, Rams defensive lineman Byron Young took Jones down in the backfield, and the quarterback grabbed his left calf. While it seemed to be a serious injury, when the game came back from commercial break, Al Michaels and Kirk Herbstreit shared that Jones could get up under his power and jog off the field.
mac jones injury pic.twitter.com/CxbaWKPWoO
— ◇ (@F0RGIAT0) October 3, 2025
Furthermore, sideline reporter Kaylee Hartung reported that while Jones was on the sideline during the ensuing Rams possession, he focused on ingesting electrolytes while the medical staff used a massage gun on his calf, suggesting the former New England Patriots QB suffered a cramp and not a more serious injury.
Jones has been impressive for San Francisco on Thursday Night Football, completing 21 of 31 passes for 232 yards and two touchdowns through he first three quarters. Even better, he’s avoided getting sacked and has not had any turnovers. If this play continues, the 49ers may have to consider who should be the starter between Purdy and Jones.
However, should Jones take another hit and be forced to miss some snaps, Martinez would be in line to receive the first NFL snaps of his career. Martinez signed with the Stallions of the UFL on Dec. 24, 2023. He would help lead Birmingham to a 6-1 record as a starter on their way to a league championship.
He completed 58.5% of his passes for 1,748 yards, 15 touchdowns, and three interceptions, and added 528 yards and three touchdowns on the ground. He was named to the 2024 All-UFL team and would earn UFL Championship Game and UFL MVP honors.

