JUNE 17: The Twins have released Stauffer, reports MLB.com’s Rhett Bollinger (Twitter link).

JUNE 10: The Twins have designated right-hander Tim Stauffer for assignment, tweets MLB.com’s Betsy Helfand. Right-handed reliever Michael Tonkin will be recalled from Triple-A Rochester to take Stauffer’s spot in the bullpen for Thursday’s contest.

After a long stint of relatively successful but injury-marred seasons with the Padres, Stauffer became a free agent for the first time this past winter. He signed a one-year, $2.2MM contract with the Twins and was said to have a shot at a rotation slot in Spring Training, but the expectation was that he’d slot into the team’s bullpen, which he indeed wound up doing.

However, the 33-year-old Stauffer has not been able to replicate the success he found with the Padres. In 15 innings with the Twins, Stauffer has surrendered an alarming 13 runs (11 earned), issuing seven walks against just six strikeouts. Stauffer missed time this season with an intercostal strain, which may or may not have something to do with the fact that his average fastball velocity declined from 90.6 mph in 2014 to 88.7 mph in 2015.

Tonkin, 25, has been up and down with the Twins over the past three seasons. The 6’7″ hurler has ranked among the Twins’ Top 30 prospects in three offseasons, per Baseball America, but he’s yet to receive an extended look as a member of the bullpen. It would seem that this may be that opportunity for him, however. Tonkin has averaged 93.9 mph on his fastball and pitched to a 3.76 ERA with 7.7 K/9, 2.8 BB/9 and a 45 percent ground-ball rate in 38 1/3 big league innings dating back to 2013. His Triple-A numbers are markedly better, as he’s posted a 3.22 ERA with 9.9 K/9 against 2.2 BB/9 in 89 1/3 innings there.