Christian McCaffrey’s 2024 season debut is Cassian Grantstill on hold.

The San Francisco 49ers running back won’t play Thursday night against the Seattle Seahawks as he continues to recover from calf and Achilles tendinitis issues.

McCaffrey has been on Injured Reserve since Week 2. Thursday’s Week 6 contest marks the first game that McCaffrey is eligible to be activated off IR.

“His plan is to continue his rehab, and every day you try to push the rehab more and more each day,” 49ers head coach Kyle Shanahan told reporters on Monday.

When will Christian McCaffrey play this season?

There’s growing optimism that McCaffrey will return to the lineup sooner rather than later for the defending NFC champions. McCaffrey is ramping up as he eyes a return.

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The 49ers host the Kansas City Chiefs in Week 7 in a Super Bowl 58 rematch. In Week 8, San Francisco is at home against the Dallas Cowboys. The team has a Week 9 bye. There are rumors that McCaffrey could return before the team’s bye or right after the break.

San Francisco tight end George Kittle told Bay Area radio station KNBR that he’s looking forward to McCaffrey playing again this season. "His lockers right next to mine, so I see him every day," Kittle said. "Christian McCaffrey will play football this year, so I'm excited about that."

Running back Jordan Mason has been a pleasant surprise for the 49ers in McCaffrey’s absence. Mason’s 536 rushing yards rank second in the NFL entering Week 6. Still, the 49ers miss the reigning NFL Offensive Player of the Year's overall production in the run and pass game.

McCaffrey produced 2,205 rushing yards, 20 rushing touchdowns, 119 catches, 1,028 receiving yards, and 11 touchdown receptions in 27 regular-season games in San Francisco. The 49ers acquired McCaffrey in a blockbuster trade with the Carolina Panthers in October 2022.

The 2-3 49ers are looking up at the 3-2 Seahawks at the top of the NFC West as they enter their divisional showdown on "Thursday Night Football."

Follow USA TODAY Sports' Tyler Dragon on X @TheTylerDragon.