Player tiring in the end, one of the Yankees missing second half (5)
I believe the answer is:
gamer
'player' is the definition.
(I've seen this in another clue)
'tiring in the end one of the yankees missing second half' is the wordplay.
I cannot really see how this works, but
'one' could be 'me' (a setter might use 'one' to humourously mean 'me') and 'me' is found in the answer.
'second half' could be 'a' (2nd letter of 'half') and 'a' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for gamer that I've seen before include "I bet" , "player using computer" , "One role-playing on computer" , "One having fun with computer" , "Keen computer player" .)