Team frequently dealt with No. 2! (6)

Here is my best explanation:

'team' is the definition.
(eleven is a kind of team)

'frequently dealt with no 2' is the wordplay.
'frequently' means one should take alternating letters (letters selected at a regular frequency).
'with no v' becomes 'even' (I can't explain this - if you can you should believe this answer much more).
The alternate letters of 'dealt' are 'el'.
'el'+'even'='ELEVEN'