Concussion? He'll be good in a few days.
That really depends on the concussion. Yes some concussions can be recovered from in a few days, but others with bad side effects can linger for weeks, month or a lifetime. Would hope we are at the point in medical science that we don't brush off a bruising of the brain as something that simply heals in a few days. The stories say he is out indefinitely.
"The return to participation protocol involves several steps of increasing exertion -- from a stationary bike, to jogging, to agility work, to non-contact team drills.
With each step, a player must be symptom free to move to the next step. If a player is not symptom free after a step, he stops until he is symptom free and begins again at the previous step of the protocol (i.e., the last step he passed without any symptoms).
While the final return-to participation decision is to be made by the player’s team physician, the team physician must discuss the return-to-participation process and decision with Dr. Jeffrey Kutcher, the Director of the NBA’s Concussion Program, prior to the player being cleared for full participation in NBA Basketball.
It's important to note that there is no timeframe to complete the protocol. Each injury and player is different and recovery time can vary in each case."
http://www.netsdaily.com/2015/12/16/10315670/shane-larkin-suffers-concussion-out-indefinitely