I play in three bands and fortunately I'm replaceable in all of them because we, including the deps, are professionals. 'Fortunately' because there are sometimes diary clashes within the three bands and sometimes a family commitment intrudes - and sometimes I break my arm, as just gone by. We manage but we have this A-Team thing: however good the dep, the band never sounds as good as when all the regulars are together which, fortunately, is most of the time.