His injury will only keep him out for 3 weeks. I dont see why he can't be considered a regular as he tends to return to form quick and is reliable. Hopefully he gets over these injury issues but I dont think he is near the end as people are suggesting. I think he is going to be able to be a great defender for many years to come.
This is all a follow on from his previous injury, he picked up another one at the end of last season and wasn't 100% for the final. Then going on a break and coming back isn't giving the muscles time to fully get up to match speed. We probably won't see the best from him for 2-3 months.