Right now, goal-line technology is used during games to review whether or not the ball crossed into the goal. The IFAB announced in June that testing would begin on in-game video replays to review goals, penalties, fouls and more in several leagues around the world. The governing body isn't expected to decide whether or not the Video Assistant Referees (VARs) system will be officially approved for use until 2018 or 2019. However, the Associated Press reports that mangers will have access to video replays for tactical reasons, but they won't be able to use them to argue calls. I'm sure they'll abide by that guideline with no issues.
FIFA enacted protocols two years ago that allow referees to stop a match for three minutes while a potential head injury is assessed. IFAB says that even with that change, there have been cases where a player shouldn't have been allowed to continue. Until the VARs system is approved, officials won't be able to consult replays that are available for medical reasons.
"We have seen enough examples where potentially if the doctor was able to use video he might have made a decision not to put a player back on the field," IFAB secretary Lukas Brud explained to the AP.