Marcum has 58 career major league wins for Toronto, Milwaukee and the New York Mets. He underwent shoulder surgery in 2013 and made just eight appearances last season for Triple-A Columbus after signing a non-roster deal with Cleveland in December. The 32-year-old right-hander has made 161 career starts.
He had his best season in 2011 for the Brewers, going 13-7 and pitching 200 innings.
The 30-year-old Molleken has spent his entire career in the minor leagues since being drafted by Pittsburgh in 2003. The righty has spent time in Colorado and Milwaukee's organizations and made 28 appearances for Japan's Nippon Ham Fighters in 2012-13.