The most common and most likely answer to this crossword clue is the 10 letter word ORGANISERS
I've seen this crossword clue in The Daily Telegraph
O
R
G
A
N
I
S
E
R
S
Buddy explains!

The straight part
We know that "Managers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case managers = organisers.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 ORGANISERS mean?
ORGANISERS noun- A person who arranges the details of a public event.
- A hand-held micro-computer that will perform specific tasks; can be used as an electronic diary, alarm clock, recorder of memos and notes, a portable database etc.
- A group of cells that, together with the evocator, control differentiation in the embryo; the inductor