Depends on the tactics you would use.
If you are playing attacking, striker would normally be in the final 3rd of the pitch...not much fitness to lose.
If playing defensive, striker would end up in own half of the pitch most of the times and end up losing more fitness.
Of course, high press loses more condition than low press.

I have a similar striker with 1% in all grey areas and he scores well too.
This is his 11th season in my side and usually these players transition from good to great players after a few seasons.