The San Francisco 49ers reportedly told star wideout Brandon Aiyuk in August, while he was holding in during extension negotiations, that he had a five-day window to report back to practice or he wouldn't be eligible for the 2024 season.

"Did you know he got the five-day letter in the middle of August that he had to practice or he wouldn't be able to play this year?" ESPN's Adam Schefter said of Aiyuk during a Monday appearance on The Pat McAfee Show. "Yeah, he did. You get a five-day letter. It means you better get back to practice or the team has the right to place you on the list and you lose the year. That happened too."

Aiyuk had been able to avoid the $40,000 fines he would have otherwise faced for not practicing throughout training camp because he was dealing with back and neck soreness. But once the Niners made their final roster cuts down to 53 players and Aiyuk was medically cleared, the team had the right to impose fines or suspensions for missed time.

ESPN's Nick Wagoner broke that down in further detail:

"Under the terms of the collective bargaining agreement, once the league switches out of training camp and into regular-season mode, teams can begin fining players for 'unexcused missed activities,' which would include walk-throughs, curfews, practices and meetings. Those fines can reach up to $16,009 for each activity missed, with a maximum total fine for a single day of $45,769 if a player misses multiple events on the schedule. From there, teams also have the ability to suspend players for conduct detrimental to the team."

The CBA allows teams to suspend players for conduct detrimental to the team for up to four weeks, alongside fining such a player up to a week's salary. The CBA additionally notes that a club cannot impose either fines or suspensions for conduct detrimental to the team until a player reaches a fourth violation in a given category.

It was ultimately a moot point once Aiyuk agreed to a four-year, $120 million extension on Aug. 29. But even that agreement came down to the wire, as the Niners reportedly told the star wideout he could either take their final offer or be traded to the Pittsburgh Steelers, as Jay Glazer reported for Fox Sports on Sunday:

All's well that ends well. Aiyuk got his new deal, returned to practice and is expected to play in Monday night's matchup against the New York Jets, albeit in what is expected to be a slightly reduced role.

"Don't know [how much he will play] yet," head coach Kyle Shanahan told reporters over the weekend. "He plays most of the game usually. Probably be surprised that same amount, but he's in good shape. He's had a really good week. His soreness hasn't been too big. After each practice he's pushed it real hard, do some stuff extra after and he looks good and he's ready to go."