The best news is Anderson does not expect the blister to affect his next start.
"It started bothering me in the bottom of the sixth, and then I started throwing some breaking balls in the seventh and it kind of caught," Anderson said. "I hopefully got it before anything major. They drained it and I don't foresee it being any kind of a problem."
Anderson left after walking Russell Martin for the third time in the game, with the Rockies leading, 1-0. He might not have pitched much longer, anyhow, since he was at 102 pitches when he was pulled.
Tommy Kahnle completed the seventh by forcing a Jordy Mercer fly ball and striking out Pedro Alvarez. The Rockies scored seven runs in the bottom of the seventh.
Anderson retired 12 of the first 13 hitters he faced before Neil Walker singled to lead off the fifth. Two batters later, he forced a Mercer double-play grounder -- a replay challenge tried to make it a triple play, but was unsuccessful.
In his first outing at Coors, the Twins game, Anderson said pitching at Coors Field was an adjustment. Call it an adjustment made.
"I was down in the zone, my stuff was getting crisper -- better and better -- and my velocity is coming back," Anderson said. "Apparently, I hate strikeouts [he had one] and I'm scared of Russell Martin. Other than that, it was pretty good."
Rockies catcher Wilin Rosario said, "He threw a lot of strikes -- so many strikes, sometimes I need balls and he's still throwing strikes. I'm enjoying catching him. I feel fresh, like I could go catch again. It was a fun, quick tempo."
Anderson can strike out hitters if called upon to do so. He fanned eight the last time he faced the Pirates.
"I'm glad we don't have to see him anymore," Pirates manager Clint Hurdle said. "He's been as effective as any pitcher we've seen this season."
Anderson's two stellar starts against the Pirates came on the heels of strong work by lefty Jorge De La Rosa, who held the Pirates to one run in six innings last Friday in a game the Rockies lost, and struck out 11 in 7 1/3 innings of a win against the Nationals on Wednesday.
The Rockies acquired Anderson, 26, from the Athletics during the winter in hopes he could provide front-end talent to the rotation. He broke his index finger in his third start of the year. But if Anderson can stay healthy -- Friday was his first win since last April 7, before foot and ankle injuries hampered his season with the A's -- he gives the Rockies another lefty stalwart at the top of the rotation.
Although De La Rosa and Anderson -- De La Rosa more prominently -- have been mentioned in reports of possible trades, the Rockies could easily have both back next season. De La Rosa will be a free agent, but the club could use a $14 million qualifying offer, which would ensure Draft pick compensation if he were to leave, as the basis for a new deal. The club has a $12 million option on Anderson.