The Blue Jays placed reliever Darren Oliver on the 15-day disabled list on Friday with a left shoulder strain, clearing roster space for Sean Nolin, whom the club already had announced would start Friday night's game against the Orioles.
The DL stint is retroactive to Sunday. The 42-year-old southpaw has a 3.18 ERA in 17 appearances this season.
To make room for Nolin on the 40-man roster, the Blue Jays transferred left-hander J.A. Happ to the 60-day DL. Happ has not thrown off a mound since he was struck in the head by a comebacker two weeks ago. While his head injuries are mostly healed, he also suffered a sprained right knee that has delayed his return.
Toronto selected Nolin's contract from Double-A New Hampshire, where he was 2-0 with a 1.17 ERA in three starts. Friday will be the Major League debut for the 23-year-old lefty, the club's sixth-round pick in the 2010 First-Year Player Draft, who is ranked by MLB.com as Toronto's eighth-best prospect.