It’s common practice for the NFL and teams to be in contact after games about injury designations. However, there’s no indication the league has opened any formal investigation into the San Francisco 49ers over running back Christian McCaffrey’s designation ahead of the team’s season opener, according to a league source Tuesday.

McCaffrey was officially listed as questionable ahead of the matchup against the New York Jets. The accuracy of that designation was called into question Monday night after backup Jordan Mason, who rushed for 147 yards and a touchdown, said he was told he would start Friday during a postgame interview with the broadcast crew.

49ers coach Kyle Shanahan said after the game he didn’t tell Mason he would be starting but instead told him to be ready as he anticipated he’d play more. Mason declined to answer a follow-up in his postgame news conference about his comments to the broadcast team.

McCaffrey is “day to day” with the calf and Achilles injuries that kept him out, Shanahan said Tuesday, but he would’ve been able to play if it had been a playoff game.

“You know, it’s not just a calf. It’s his Achilles and, you know, the Achilles has tendinitis and that stuff comes and goes,” Shanahan said. “And when it’s acting up, it’s something you have to be very careful about. Christian’s pretty diligent about that stuff.

“And if it was a playoff game, he made it very clear to me – he believed he could go. But you hear that type of stuff and it’s not a playoff game and it’s Week 1, especially when you’re dealing with the lower extremities like that, it was a tough decision but hearing all the words and stuff, in the long run it made it easy.”

McCaffrey was limited in practice during the run-up to the game.

Shanahan called the calf/Achilles issues that kept him out of training camp “similar” to the calf injury he suffered in Week 17 last season. He didn’t play in Week 18, although San Francisco rested most of its starters in that contest, but returned for the divisional playoff game against the Green Bay Packers, rushing 17 times for 98 yards and catching seven passes for 30 yards.

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