The most common and most likely answer to this crossword clue is the 7 letter word WHINGER
I've seen this crossword clue in The Daily Telegraph
W
H
I
N
G
E
R
More clues leading to the result WHINGER
- Footballer goes round hospital — he has irritating complaint
- Coach finally accepted by team member, a fretful type
- Husband punches footballer and he moans
- One complaining of coach ultimately punching footballer
- Footballer around half-time’s first person to grumble
- Sort of person who complains of footballer outside hotel?
Buddy explains!
The straight part
We know that "One complaining" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one complaining = whinger.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.