Tue 2/14/12 9:52 AM

The Mariners are keeping tabs on Hong-Chih Kuo's mechanics this spring. Kuo is working his way back from elbow surgery, but he also dealt with an anxiety disorder last season which impacted his ability to find the strike zone. The 30-year-old left-hander threw his first bullpen session on Sunday and Mariners' bullpen coach Jamie Navarro was pleased with what he saw. "We're just watching the arm slot and his mechanics and how he's dealing with that," said Navarro. "We're going to keep a close watch on him through the spring. He has to keep the same arm slot and the mechanics. That's huge." Kuo is just one year removed from being one of the most dominant relievers in the game, so he could be a tremendous bargain if he returns to form.