@prepper_jack thanks for that i only looked at medical centre for injuries till now.
i only have 3,19 year olds in first team squad but many between 20-25. couple of the 19yos have been playing almost every game as they are the best players i have in their position but will rotate them more going forward.
i did notice some players losing stats (all ages) mid season. nothing catastrophic though. but thinking back i may have destroyed a couple of high potential youngsters along the way. they didn't drop in any stats but their potential disappeared, so they stayed at squad player level in championship.