The Toronto Blue Jays bolstered their pitching depth on Monday, claiming a pair of right-handers off waivers.
Castro, 25, made his MLB debut last season, pitching one inning and allowing two runs for the Tigers in a July game against the Kansas City Royals. In 2019, Castro made 18 starts and pitched in 27 games for double-A Erie, where he had a 4.40 ERA, 116 strikeouts and 65 walks in 102.1 innings.
A native of Venezuela, he originally signed with the Tigers as a free agent in 2011.
Lockett, 26, pitched in two games last season for the New York Mets before he was claimed by the Mariners on Sept. 1. Over 16.1 total innings in 2020, he posted a 4.96 ERA and a 1.53 WHIP.
The moves give the Blue Jays a full 40-man roster.