White Sox acquire flame-throwing Thyago Vieira from Seattle Mariners

When the White Sox blew past their 2016-2017 international pool limit and signed Luis Robert to a mega 26 million dollar deal, the penalty was that they were capped at $300k per player on the international market for the 2017-2018 and 2018-2019 periods. Luckily for them, nothing prevents them from dealing the excess cap room (they have a 4.75 million dollar pool) to needy teams and Rick Hahn acquired SS Yeyson Yrizarri from Texas and RHP Ryan Burr from Arizona this way. Today the White Sox struck again using their international bonus clearance, acquiring Brazilian RHP Thyago Vieira from the Seattle Mariners, who presumably are trying to convince Japanese superstar Shohei Ohtani to come to the Pacific Northwest. Jonathan Mayo of MLB.com reports the pool amount to be $500k.
Thyago Vieira was signed by the Seattle organization out of Brazil as a 17-year-old in 2010. He spent two seasons in the now-defunct Venezuelan Summer League before making his stateside debut as a starter in 2013. It was quickly determined he was destined for a relief role and after a couple years with poor command and so-so results, Vieira had a breakout 2016 campaign in High-A ball that saw him post a 2.86 ERA with 53 strikeouts to just 7 walks over 44.1 innings. His 2016 season culminated with a brief but highly successful Arizona Fall League stint that included a hitting 104 MPH with his fastball, which apparently was inspired by Aroldis Chapman.

“The day before I saw in the World Series I saw Chapman throwing hitting 104. I said, I’m going to do this the next day (in the Arizona Fall League),” Vieira said. “I said ‘I’m going to throw as hard as I can.’ But when it happened, I didn’t believe it. When they told me, it was amazing.”

Vieira built off his 2016 momentum by pitching well enough at AA Arkansas to be selected to the World Team in the MLB Futures Game. After a stop in AAA Tacoma, he ended his 2017 season with one scoreless appearance in the major leagues.


Vieira’s repertoire unsurprisingly is centered around his electric plus-plus fastball. MLB Pipeline graded it at an 80, which is at the very top of the 20-80 scouting scale. Vieira not only possesses high octane velocity, but as evidenced by the video above (courtest of BA’s Josh Norris) his fastball has plenty of movement. It is a true difference-maker pitch and he could likely be a bullpen piece with just average command of it, but his ceiling will be dictated by the development of a secondary offering (and, of course, command of both). He has reportedly toyed with a power curveball, a split-fingered fastball, and a change-up, but most recently he appears to be throwing a hard slider with some success.
This spring Vieira will be enrolled in the Don Cooper Center For Kids Who Throw Real Hard and will have an opportunity to break camp with a young bullpen or continue working on his stuff in AAA Charlotte. Considering the cost (or lack thereof), this is a fantastic acquisition from the White Sox standpoint, and could turn in a complete steal if Vieira is able to harness his raw stuff into a closer role.
MLB Pipeline just added Vieira at #20 on their version of the Top 30 White Sox prospects list.
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