Detroit Lions Concussion Return-To-Play Timelines: 2023-2025
How many days can we expect a Lions player to miss after a concussion?
Concussion management has been in a state of flux over the past 2+ decades. When I was grinding through medical school at the University of Michigan in early 2000, the accepted standard-of-care allowed a return-to-play after just 15 minutes of being asymptomatic following a concussion. Now, the standard return-to-play is around a week or longer.
From a fan standpoint, we want to know when we can expect a Detroit Lion to return-to-play following a concussion. Evaluating recent data helps more accurately predict concussion timelines.
Here is a Detroit Lions concussion analysis over the past 3 seasons, starting with summary and conclusions, followed by case-by-case details.
When do Detroit Lions return to play after a concussion?
In italics are extraneous factors that may have delayed a return-to-play. Define Day 1 as the day after the concussion.
Played in NFL game in 9 days - Hendon Hooker (2024)
10 - Alim McNeill (2024)
11 - Trevor Nowaske (2024)
15 - Alex Anzalone (2024)
17 - Thomas Harper (2025)
18 - Terrion Arnold (2025), shoulder
21 - Brian Branch (2024), illness + bye
56 - Khalil Dorsey (2025), wrist
indefinite, end of season - Thomas Harper (2025)
indefinite, end of season - Alex Anzalone (2025)
indefinite, released - Morice Norris (2025)
never, retired - Antoine Green (2024), neck
uncertain, training camp - Penei Sewell (2023)
Detroit Lions 3-Year Concussion Analysis Key Takeaways
The median return-to-play is 11 days for concussions without extraneous factors.
No Lion in the past 3 seasons has returned to play in under 9 days.
For the 2026 Lions season, missing 1 game would be the expectation - unless there is a bye or mini-bye.
Detroit Lions Concussion Case Studies - 2025 Season
#1. Morice Norris
Concussion date: August 8, 2025
Return-to-play: indefinite, waived
In this preseason game, Norris notably had a seizure in the immediate seconds of the concussion. Fortunately, he appeared to recover quickly and was back with the team within days. While the seizure was disturbing to witness, studies have shown it is very unlikely to result in long-term issues like recurrent seizures (epilepsy).
He might have been able to return to play within 2-4 weeks, but he did not make the team and was out of the NFL for the entire season.
#2. Khalil Dorsey
Concussion date: September 28, 2025
Return-to-play: 56 days
Dorsey had a full practice leading up to the next game, which put him firmly on track to return in just 7 days. However, he suffered a wrist injury during the week that landed him on IR.
#3. Terrion Arnold
Concussion date: November 9, 2025
Return-to-play: 18 days
Arnold took longer to return from the concussion than expected - likely related to the right shoulder injury that threatened his season just a month prior. After his first game back from the concussion, he decided to have shoulder surgery which ended his season.
#4. Thomas Harper
Concussion date: December 4, 2025
Return-to-play: 17 days
Harper had a mini-bye after this concussion and looked poised to return at the 10 day mark with 3 limited practices. However, caution may have prevailed and he took the next game off.
#5. Thomas Harper
Concussion date: December 25, 2025
Return-to-play: indefinite, end of team’s season
This was Harper’s 2nd concussion of the month. The season’s final game was in 10 days in which he did not play. Even if the finale was an important game, he likely would not have played. The multiple concussions within a short time span leads to concerns for a lowered concussion threshold - meaning it’s easier to get another concussion.
#6. Alex Anzalone
Concussion date: December 25, 2025
Return-to-play: indefinite, end of team’s season
The next and final game of the season was in 10 days in which Anzalone did not play. The meaningless nature of the finale may have been a factor.
Detroit Lions Concussion Case Studies - 2024 Season
#1. Hendon Hooker
Concussion date: August 8, 2024
Return-to-play: 9 days
No video here as the moment of injury was uncertain. Hooker played nine days later in the next preseason game.
#2. Antoine Green
Concussion date: August 8, 2024
Return-to-play: never, retired
This concussion included a significant neck injury that caused Green to retire from the NFL.
#3. Alex Anzalone
Concussion date: September 15, 2024
Return-to-play: 15 days
One of the friendly fire incidents of the 2024 season caused Anzalone to miss one game.
#4. Brian Branch
Concussion date: September 22, 2024
Return-to-play: 21 days
This was an interesting case. Branch passed through the 5-phase concussion protocol within a few days after the concussion and appeared set to play in the next game in 8 days (Monday Night). However, an illness popped up late in the week, and he ended up missing the game. The missed game may have been due to a combination of illness and the recent concussion.
It’s possible that the “illness” symptoms were actually post-concussion symptoms. Many concussion symptoms can be non-specific and vague such as headache, nausea, dizziness, and fatigue. These symptoms show up in many routine illnesses which can make attributing their root cause difficult to impossible.
Despite passing through the concussion protocol, there may have been concern he was still having post-concussion symptoms, which would have made sitting him prudent.
Branch very likely would have been ready to play at the 14-day mark, but the bye delayed his return to 21 days.
#5. Alim McNeill
Concussion date: December 5, 2024
Return-to-play: 10 days
Officially, the injury was reported as a “head” during the game, not a concussion. McNeill had a suspected TMJ (temporomandibular joint) issue earlier in the year so there was suspicion it could be related to that.
After the game, he was then officially diagnosed with a concussion. The next Lions game was in 10 days in which he played and unfortunately tore his ACL.
#6. Trevor Nowaske
Concussion date: December 11, 2024
Return-to-play: 11 days
Nowaske suffered his concussion during the practice week. He missed one game and returned to play in 11 days.
Detroit Lions Concussion Case Studies - 2023 season
#1. Penei Sewell
Concussion date: July 28, 2023
Return-to-play: uncertain
This concussion occurred early in training camp. Like the rest of the starters, he didn’t play in preseason, which means we don’t know when he would have returned-to-play. His first game action was 6 weeks later in Week 1, and he didn’t miss a game all year.