the 5* fast trainers of lv6 are from 12-15 M' so I believe your player is 2nd class fast trainer (good but not the faster).
Ofc with almost 7*, at this point he won't be so fast as he has high quality but from next season he will be quite good.
pros :
- He is young, 18 y.o.
- It's early in the season
cons :
- He has only one position
- His sa isn't useful for a defender (I prefer "aerial" or def.wall" )
- He isn't like the recommended players so you have to pay also the money besides the 79 T
maybe buy him and make him left side winger next season (DL-ML-AML)