Seo designated for assignment
A pair of starters, left-hander J.P. Howell and right-hander Andy Sonnanstine, were promoted from Triple-A Durham. Reliever Jae Kuk Ryu was optioned to Durham.
Howell, 3-5 with a 3.96 ERA, was recalled to start Sunday's game against Kansas City. He made eight starts with Tampa Bay last season, going 1-3.
Sonnanstine had his contract purchased and will make his major league debut Tuesday at Toronto. He is 40-18 with a 2.56 ERA in 84 career minor league games.
Seo was dropped from the rotation last week, after going 3-4 with an 8.13 ERA in 11 games, including 10 starts. Ryu, 1-1 in 15 relief appearances, will work as a starting pitcher in the minors.
"We saw it all the way through," Tampa Bay manager Joe Maddon said. "We wanted to make sure the guys down below were ready. These two guys were deemed ready and we felt it was necessary to do something at the point."
Left-hander Jon Switzer was reinstated from the 60-day disabled list and optioned to Durham. He had been sidelined by a left shoulder injury.
Copyright 2007 by The Associated Press
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