Which is correct?
Could you tell me which is correct?

1)
a sport player
a sports player

2)
Sakuragi could be an excellent sports player. However, he wastes his talents at fighting with others.
Sakuragi could be an excellent sports player. However, he wastes his talents with fighting with others.
Sakuragi could be an excellent sports player. However, he wastes his talents fighting with others.

Thank you!

Question

Which is correct?
Could you tell me which is correct?

1)
a sport player 
a sports player

2)
Sakuragi could be an excellent sports player. However, he wastes his talents at fighting with others.
Sakuragi could be an excellent sports player. However, he wastes his talents with fighting with others.
Sakuragi could be an excellent sports player. However, he wastes his talents fighting with others.

Thank you!

Answer

If you are talking about more than one sport you would say sports. You can also say "Sakuragi could be an excellent sportsman...". (Or sportswoman)

If you want to be more specific about the sport then it gets complicated...

Football - Footballer/Football player
Tennis - Tennis player
Golf - Golfer
Rugby - Rugby player

Answer

1) You can use both. 'Sport' is more English and 'Sports' more American ,but both are Ok .

2) The third sentence is correct ! 
"He wastes his talents fighting ...."