Illness having Mike clearly in bed (9)
I believe the answer is:
complaint
'illness' is the definition.
(thesaurus)
'mike clearly in bed' is the wordplay.
'mike' becomes 'm' (phonetic alphabet: alpha, bravo, charlie etc.).
'clearly' becomes 'plain' ('plain' can be a synonym of 'clearly').
'in' means one lot of letters goes inside another.
'bed' becomes 'cot' (cot is a kind of bed).
'm'+'plain'='mplain'
'mplain' going inside 'cot' is 'COMPLAINT'.
'having' is the link.
(Other definitions for complaint that I've seen before include "Minor ailment" , "Objection" , "Grievance; illness" , "Compliant in grievance" , "Protest" .)