This is my first year watching Cubs games on Marquee after taking a sabbatical for about 3 years and what I have noticed is that JD and Boog are the main announcers, but every now and then one of them will have the day or a few days off (in the case of JD) and someone else will come in (Joe Girardi for the days JD was missing, Zaidman today). Are more people than only JD and Boog contracted to call games on Marquee?