SANTA CLARA -- Near the back corner of the 49ers’ locker room, a defensive back opened his backpack to retrieve his latest pay stub. He tore open the envelope to confirm what he already knew.

Antone Exum Jr., who makes his living as a professional football player, worked for free last week.

Pay to the order of Antone Exum Jr. in the amount of zero dollars, zero cents.

For the vast majority of NFL players, their salaries aren't guaranteed. They receive 1/17th of their pay weekly during the regular season. Exum, a fifth-year pro, makes $705,000. Before taxes, that comes out to $41,470 weekly.

But the 49ers defensive back played for free last week while making his sixth start of the season because the NFL fined him $53,472 for a hit on Denver Broncos wide receiver DaeSean Hamilton in Week 14. Exum also was penalized 15 yards on the play, so he was punished twice for the same foul.

It looked -- and felt to Exum -- like a clean hit.

“It was a pretty clean shot,” he said. “ It just looked like ... that much? For that?"

Hamilton caught an 18-yard pass on a post pattern, and Exum stepped up from his free safety position in the deep middle of the field to hit him. Exum clearly turned his left shoulder into Hamilton and did not lead with his helmet.

“They are trying to protect guys,” Exum said. “I understand, but I hope they thoroughly review the film and fairly review the case that we presented at the appeal when they think about reducing it.”

NFL appeals officer Derrick Brooks, the Hall of Fame linebacker, heard Exum’s appeal last week. Exum expects to hear to the result of his appeal in the coming days.

Exum was treated as a second-time offender after the NFL fined him $26,739 earlier this season for a hit away from the ball on Kansas City Chiefs receiver Sammy Watkins in Week 3.

Exum said he knew as part of the 49ers' preparation -- personnel, formation, and down and distance -- that quarterback Patrick Mahomes would look to get the ball to Watkins across the middle. Exum jumped the route and hit Watkins, as Mahomes went to his second read to throw to Chris Conley. Exum was penalized for unnecessary roughness.

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Brooks also heard Exum’s appeal on that infraction. The fine was reduced to $5,000.

“I’m not going to complain about that,” Exum said. “I know my intent. I don’t have any bad intent going to the head or neck area. I’m not that type of player to be targeting. It hurts me as much as it would hurt the guy I’m hitting. And it hurts the team.”

The fine money was reimbursed later. Exum hopes another successful appeal will show up in his final paycheck of the season.