Worth noting

• New leader atop the totem pole of impressive relief candidates? Phil Irwin struck out seven in 3 2/3 innings on Monday -- going one out longer than starter Jeff Locke -- giving him nine strikeouts in eight innings, and manager Clint Hurdle's attention.

"We like what we've seen," Hurdle said of the 26-year-old righty who, much like Gerrit Cole, stepping-stoned through the farm system from Class A to Triple-A last season, but spent most of it with Double-A Altoona. "He's in contention for numerous situations."

Irwin, a 21st-round pick in 2009, has pitched almost exclusively as a starter in the Minors but, Hurdle said, "You can only start so many guys."

• Jeff Karstens (biceps tendinitis) threw a "routine bullpen" on Monday and is scheduled to make his spring pitching debut in a Minor League exhibition on Wednesday.

• Chase d'Arnaud was scheduled for a late-afternoon MRI on Monday on the sprained left thumb he suffered during rundown drills Friday.

"It doesn't feel as tight as it did before," d'Arnaud said, holding up a left hand wrapped in a fat ice pack.

• In pregame ceremonies, Miguel Bonilla, pitching coach for the Bucs' Gulf Coast League club, was awarded the third annual Chuck Tanner Award, which goes to a Minor League staffer who best exemplifies the former Pirates manager's optimism, work ethic and leadership. The first two recipients had been Mike Lum and Tom Prince.

• The May 4 game at PNC Park against the Nationals has been changed from a 7:05 p.m. to a 4:05 p.m. ET start to accommodate FOX's national telecast. As a result, the scheduled Zambelli Fireworks had to be cancelled with the earlier start.

Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.