White Sox acquire Vieira from Mariners

One of the best farm systems in the game has added even more gas.
The White Sox have acquired Thyago Vieira, a hard-throwing right-handed reliever, from the Mariners in exchange for international bonus pool money, the clubs announced Thursday.

Vieira was ranked by MLB.com as the No. 8 prospect in the Seattle system, thanks to a fastball that the site rates as an 80 on the 20-80 scouting scale. Representing his native Brazil at this year's Futures Game, he threw eight of the 20 hardest pitches thrown -- each of which came in at 99.5 mph or faster. His breaking ball is also considered above-average, though control concerns and the fact that he throws two pitches have kept him in the bullpen for most of his career. (His last start came in 2013 with Class A Short Season Everett.) 
The 24-year-old posted a 4.00 ERA and 1.30 WHIP with 46 strikeouts and 22 walks in 54 innings between Double-A Arkansas and Triple-A Tacoma in 2017. He made his Major League debut on Aug. 14, pitching one perfect inning with one strikeout against the Orioles. He was optioned back to Tacoma the following day and didn't appear in the Majors for the remainder of the campaign. Not surprisingly, he was much tougher against right-handers this year, holding them to a .191 average and .260 slugging percentage, compared to .307 and .440 versus lefties.

The addition of Vieira gives the White Sox yet another power arm in a system already in the conversation as the best in the game. Vieira, Michael Kopech, Dylan Cease, Alec Hansen, Zack Burdi and Aaron Bummer have all received grades of 70 or above for their fastball from MLB.com.
This is the second trade the Mariners have made in the last two days. Seattle acquired corner infielder Ryon Healy from Oakland for shortstop prospect Alexander Campos and right-handed reliever Emilio Pagán on Wednesday.