The 27-year-old Leesman has spent his entire seven-year career with the White Sox after being selected in the 11th round of the 2008 Draft. He is a two-time Minor League All-Star (2011, '12) and made his Major League debut with the White Sox in 2013 (eight appearances). He also made one start for Chicago in 2014.
Pittsburgh also invited the following six players to Major League camp:
• Infielder Stetson Allie, the club's second-round pick in the 2010 Draft, who finished second among all Pirates Minor Leagues with 21 home runs for Double-A Altoona.
• Outfielder Keon Broxton, acquired from the D-backs last March, who hit 15 homers, stole 25 bases and posted a .853 OPS last season for Altoona.
• Right-hander Tyler Glasgow, the club's fifth-round pick in 2011, who is Pittsburgh's two-time reigning Minor League Pitcher of the Year. He was 12-5 with a Florida State League-leading 1.74 ERA in 23 starts last season for Bradenton.
• Infielder Gift Ngoepe, who entered last season as Pittsburgh's "Best Defensive Infielder" per Baseball America. The 2008 non-drafted free-agent signee committed only 11 errors in 131 games last season at Altoona, playing 86 games at second base and 44 at shortstop.
• Outfielder Mel Rojas Jr., the club's third-round pick in 2010, who posted career highs in hits (126), home runs (10) and RBIs (66) in 2014 while splitting the season between Altoona and Triple-A Indianapolis.
• Right-hander Adrian Sampson, the Pirates' 2012 fifth-round pick, was 11-6 with a 2.96 ERA and two complete games in 28 starts between Altoona and Indianapolis. He earned mid- and postseason Eastern League All-Star nods and was named Altoona's Pitcher of the Year. He also posted a 2.25 ERA in 10 appearances in the Arizona Fall League, where he was named to the league's Rising Stars team.
Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth. This story was not subject to the approval of Major League Baseball or its clubs.