The most common and most likely answer to this crossword clue is the 7 letter word SCULLER
I've seen this crossword clue in The Guardian
S
C
U
L
L
E
R
More clues leading to the result SCULLER
Buddy explains!

The straight part
We know that "One involved in row" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one involved in row = sculler.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 SCULLER mean?
SCULLER noun- One who sculls; an athlete who participates in sculling races.
- A boat rowed by one person with two sculls, or short oars.