Yoo started his career with the Doosan Bears in 2009 and 2010, and played sporadically out of the bullpen.

Upon returning to Doosan in 2013, he emerged as a surprisingly dominant starting pitcher, earning 10 wins and a 3.53 ERA.

Yoo has a fairly short stature for a pitcher, standing at 1.80 m, and is bulky, weighing 88 kg.

Yoo, a left-handed pitcher, makes up for this slow delivery with excellent control, and a very efficient set of change-ups and breaking balls.

[3] In college, he was an avid basketball player as well and became close friends with future KBL MVP Award winners Oh Se-keun and Kim Sun-hyung as members of the basketball and baseball teams shared the same dormitory.