The Mariners have added Joe Wieland to their 40-man roster and called him up from Tacoma to start tonight's ballgame against the A's. To make room on the 40-man, they have DFA'd Dan Robertson. Robertson is a 30-year-old outfielder who appeared in 10 games for the Mariners this season (he even batted leadoff twice!), but his age and lack of any one outstanding skill appears to have made him expendable. It's possible that he'll clear waivers and accept an assignment with Tacoma.
As for Wieland, he's a 26-year-old RHP who Jerry acquired in a trade from the Los Angeles Dodgers (for Erick Mejia) back in January. He pitched briefly in the majors in 2012, 2014, and 2015 and has started 20 games for the Rainiers this season. His minor league ERA this year isn't much to look at (5.38) but his BB rate (2.7 BB/9) and K rate (8.1 BB/9) aren't particularly alarming. For a slightly less hand-wavey explanation of his stuff, here's a tweet from Brendan:
Haven't seen him for a few months, but Joe Wieland was very up and down in Tacoma. Four pitches, wasn't consistently executing with any.— Brendan Gawlowski (@GawlowskiB) August 12, 2016
This move appears to be necessitated by the fact that Ariel Miranda (tonight's originally scheduled starter) was forced to pitch an inning in Tuesday's 15-inning affair against Detroit. Jerry and Scott must've felt like giving their pitchers a little more rest was worth this roster move. Hopefully Wieland is able to go deep into tonight's game and put together a quality start. Welcome to Seattle, Joe.