Both players were invited to major league camp, which began Monday.
The 30-year-old Matusz appeared in seven games for Baltimore and one with the Chicago Cubs last season. He is 27-41 with a 4.92 ERA in 280 big league games.
The 32-year-old Jepsen appeared in 58 games with the Minnesota Twins and Tampa Bay Rays last season, finishing 2-6 with a 5.98 ERA. He led the American League with 75 appearances and had a 2.33 ERA in 2015.
Jepsen is 28-30 with a 3.92 ERA in parts of eight seasons with three teams.