If you notice changes in your mate’s behaviour, no matter how small, don’t be afraid to check in with them.
Changes, no matter how small, can be an indication something is up. If your gut feel is they seem a bit off, it’s worth a check in.
They might start missing a few trainings or seem quieter than usual. If their behaviour is out of character, they could be finding things tough.
Are they speaking more negatively about things? Easily irritated? When someone is struggling they can find it hard to notice the positives.