Sisk becomes the eighth pitcher added to the 22 arms on the 40-man roster, giving new pitching coach Dave Eiland 30 prospects for the staff. The first official workout will be on Feb. 21 in Surprise, Ariz.
Last season, Sisk, 26, had a combined record of 7-3 with a 2.52 ERA and two saves in 41 relief outings for Double-A Northwest Arkansas (3-1, 3.77 ERA in 16 games) and Triple-A Omaha (4-2, 1.41 ERA in 25 games). That was his first venture into Triple-A.
Sisk, who had 21 saves and a 1.92 ERA for Class A Advanced Wilmington in 2009, was also in Major League camp last year.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.