Karstens returned to the mound on Tuesday after skipping two starts due to shoulder soreness and fatigue. A similar arm issue surfaced at the end of August last year, and it limited Karstens to just one inning during the season's last five weeks.
"Last year, when I broke down, I wasn't able to pitch again until the [last] series," Karstens said. "For me to come back out and feel good ... I'll go from there."
Karstens is scheduled to make another start Monday, though the Pirates haven't assured him of one more after that. The fact that Karstens said he felt pain free and strong in Tuesday's outing -- despite some obvious command issues -- could help his argument to remain in the rotation through season's end.
He has already logged a career-high 156 1/3 innings, which is 33 2/3 more than he pitched in Pittsburgh last season. If Karstens is unplugged from the rotation after his next start, the Pirates would likely fill the opening with either Aaron Thompson or Brian Burres.
Regardless of how his season ends, Karstens will remain one of the brightest stories from 2011. His ability to slide into the rotation in early April and fortify it played a large role in the team's early-season success. It also likely assured Karstens of being tendered a contract by the Pirates this offseason.