The most common and most likely answer to this crossword clue is the 10 letter word TROMBONIST
T
R
O
M
B
O
N
I
S
T
More clues leading to the result TROMBONIST
- One of the military brass, amazing Sir Tom enthrals Britain on reaching a ton
- Noted his job is on the slide
- Player in cricket side is behind doctor dressed in red
- Player isn’t robot designed to cover miles
- It’s extremely rotten to mob rock musician
- Middlesex opener bowled, cricket side is getting squeezed by medium pace player
- Marching band member possibly in mob’s playing in brisk pace
- He performs extensively on a sliding scale
Buddy explains!

The straight part
We know that "Player" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case player = trombonist.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.
What does TROMBONIST mean?
TROMBONIST noun- A person who plays the trombone.