Following a strong spring showing, Eveland began the year as Toronto's fifth starter and carried his preseason success into the early part of this season. A string of rough outings finally led the Blue Jays to designate him for assignment on May 24.
Eveland joins a Pittsburgh club that has struggled with its starting pitching this season. Entering Tuesday, the Pirates rotation had gone 10-28 with a 5.83 ERA, representing the highest ERA among National League starting staffs.
Eveland, 26, is out of options, meaning he would need to clear waivers in order to be sent to the Minor Leagues. He began the season 3-1 with a 3.82 ERA with the Blue Jays but then faltered over his next three outings, going 0-3 with a 16.39 ERA over a span of just 9 1/3 innings.
Eveland's best season came in 2008, when he went 9-9 with a 4.34 ERA for the A's. Overall with the Blue Jays, the left-hander -- acquired by Toronto in a trade with Oakland in February -- went 3-4 with a 6.45 ERA. Eveland is 16-21 with a 5.66 ERA in 92 career big league games.
The 23-year-old Uviedo has made 16 relief appearances this season for Double-A Altoona in the Pirates' system. In those outings, the righty went 0-2 with a 3.22 ERA, surrendering just 13 hits over 22 1/3 innings with 28 strikeouts against 12 walks.
Uviedo -- a native of Guarico, Venezuela -- has gone 18-13 with 31 saves and a 3.10 ERA over 158 career Minor League games between tours in the Mariners and Pirates organizations.
Jordan Bastian is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.