Master Dan could become a skilled worker (9)
I believe the answer is:
tradesman
'a skilled worker' is the definition.
(I know that tradesman is a type of specialist)
'master dan could become' is the wordplay.
'could become' indicates an anagram.
'master'+'dan'='masterdan'
'masterdan' is an anagram of 'TRADESMAN'.
(Other definitions for tradesman that I've seen before include "Dealer" , "Shopkeeper; skilled mechanic" , "Small businessman" , "A skilled worker like plasterer or joiner" , "Retailer - artisan" .)