Updated

Toronto, ON (SportsNetwork.com) - The Toronto Blue Jays have designated struggling pitcher Sergio Santos for assignment, the team announced Monday.

Santos was rocked for 18 runs (17 earned) and 24 hits in 19 2/3 innings over 24 relief appearances for Toronto this season. The right-hander also was plagued by control problems, issuing 17 walks in those 24 games.

The Blue Jays acquired Santos from the White Sox in December of 2011, shortly after he put together a 30-save campaign as Chicago's closer. He pitched in only six games the following season, however, before undergoing surgery on his right shoulder.

Pitcher Rob Rasmussen was recalled from Triple-A Buffalo in a corresponding move and will be active for Monday's game against the Boston Red Sox.

Rasmussen has gone 1-1 with a 2.61 ERA and one save in 25 games for Buffalo. The left-hander was obtained by Toronto in a trade with Philadelphia back in December.