Do you believe all this?
The number of injuries that will occur is reduced by a certain percentage after a pitch upgrade is done.
Upgrades for medical facilities lowers the risk of injuries.
Training condition and progress are improved when the training facility is upgraded.
There are many posts in this forum that indicate that all this is a 'gimmick'. Non biased users here will agree that all this is just visual and do not do what Nordeus pretend they do. You will get extra packs and additional money from upgrades and that's it.
Injuries will still occur, probably because a particular number must be respected within a period of time. You can have players with 100% condition, 100% morale, all facilities upgraded fully, use normal tackle and yet have several injuries from home matches. Your team may have 1-2 seasons with little to no injuries and suddenly you will be hit by a stream of injuries just because a particular figure has to be reached within a period of time. Injuries may also occur when the game has decided against you for particular matches; this does not necessarily have to be the match where the player was injured; it could be because of one of the next matches (especially if the next match is crucial - a decisive match for the league, a must win knock-out round match).