Though Daisuke Matsuzaka left Friday night's matchup with elbow tightness, there's reason to believe the Red Sox' starter has bounced back this season.

After one rough start in early April, Matsuzaka posted back-to-back gems before his Friday night start against the Mariners. NESN insider Peter Gammons stopped in during Red Sox First Pitch to discuss Matsuzaka's success this season, and attributes his performance to his hard work during the offseason.

"He got himself in better shape this year," Gammons said. "His throwing program's a little bit different and he's got good enough stuff to get guys out in the strike zone. For a couple of years, it didn't look like he believed that."

To hear more from Gammons on Matsuzaka's development, check out the video above from Red Sox First Pitch.