I highly suggest you buy Ivan Cavaleiro, he would be around 24 years old on your save so he's a good age. He is a left winger who can also play on the right and can also play left mid. On my save he plays for Arsenal and has destroyed my Nathaniel Clyne every time I go against Arsenal.
He is a pacy, tricky winger who is very fit and has great ratings for stamina and natural fitness, he also practically plays every match for Arsenal too so he doesn't seem injury prone at all.
He is valued at £25 mil and I'm 4 years in my save, I suggest you buy him at any cost because him and Nathan Redmond would tear opposition fullbacks apart at their full potentials.
If you have problems signing him for your Norwich side, you could buy Matheus Pereira and he would be around 19/20 years old on your save. He is a similar player to Ivan Cavaleiro by the looks of it and would be cheaper too.