The Triple-A Norfolk Tides face the Charlotte Knights, and the Double-A Bowie Baysox host the Harrisburg Senators at Prince George's Stadium.
The Single-A Frederick Keys play the Kinston Indians, and the Single-A Delmarva Shorebirds continue their road trip against the West Virginia Power.
The short-season Single-A Aberdeen IronBirds look to snap the Brooklyn Cyclones' 10-game win streak.
Orioles relief pitcher Dennis Sarfate is scheduled to pitch in an injury rehabilitation assignment for the Baysox on Saturday, according to the team. The 28-year-old right-hander is recovering from a shoulder injury, and he hasn't pitched in the major leagues since May 1.
UPDATE (4:19 p.m.): The Keys just announced that Sarfate will also rehab in Frederick on Tuesday night against the Kinston Indians.
The Baysox also announced that relief pitcher Chad Thall was selected as a replacement for the 2009 Eastern League All-Star Game in Trenton N.J.
Thall takes the place of Baysox relief pitcher Josh Perrault, who was recently promoted to Norfolk, on the Southern Division team. The 23-year-old left-hander leads the Eastern League with 12 holds, and he is 2-2 with a 3.44 ERA in 31 appearances this season. Thall has 36 strikeouts in 36 2/3 innings for Bowie.
at Charlotte Knights (7:15 p.m.)
Norfolk: Chris Tillman (6-5, 2.69 ERA)
Charlotte: Kelvin Jimenez (3-2, 4.56 ERA)Bowie Baysox (AA)
Harrisburg Senators (7:05 p.m.)
Bowie: Tim Bascom (2-1, 3.60 ERA)
Harrisburg: Erik Arnesen (4-2, 3.47 ERA)
Record: (5-6 in second half, 36-44 overall)
at Kinston Indians (7 p.m.)
Frederick: Nathan Nery (2-3, 4.48 ERA)
Kinston: Russell Young (2-3, 4.50 ERA)
Record: (6-7 in second half, 42-40 overall)
at West Virginia Power (7:05 p.m.)
Delmarva: Ryan O'Shea (5-4, 3.42 ERA)
West Virginia: Brian Leach (2-0, 1.86 ERA)
at Brooklyn Cyclones (7 p.m.)
Aberdeen: Tyler Sexton (1-2, 4.20 ERA)
Brooklyn: Wes Wrenn (0-0, 4.00 ERA)