Rather than starting on Sunday night against Clayton Kershaw, Cole threw 15 fastballs in the PNC Park bullpen under the watchful eye of pitching coach Ray Searage.
"Very good progress so far," Searage said. "The timing's off a little bit but didn't feel anything [in his arm], had good angle. Had to tell him to back off a little bit. It was very, very good."
Cole will throw a few more bullpen sessions during the Pirates' upcoming road trip through Seattle, Oakland and St. Louis, Searage said, before the Pirates lay out a schedule for a Minor League rehab assignment.
That timeline obviously puts Cole's return before the All-Star break in question, but it should make him available some time in July.
This is Cole's second trip to the disabled list, and Searage believes the 25-year-old right-hander is learning how to handle the time down.
"Let's put it this way: He's handling it better, but he's still an ornery little S.O.B. He's a competitor," Searage said. "He wants to be out there. He's watching the games that we're playing. He's just itching to get back out there. He has a better understanding of the process that he needs to go through."
Cole was 5-4 with a 2.77 ERA in 12 starts before he was placed on the disabled list. Right-hander Chad Kuhl made his Major League debut Sunday night in Cole's place and seems likely to remain in the rotation at least until Cole is ready to return.
The Pirates could use a healthy Cole back in their rotation. Their ace went 19-8 with a 2.60 ERA in 208 innings over 32 starts last season. Pittsburgh's starters entered Sunday's game with a 4.71 starters' ERA, the 10th-highest mark in the Majors.
Kuhl became the ninth pitcher to start for the Pirates this season, already one more than Pittsburgh used all of last season.
Pirates right fielder Gregory Polanco was out of the starting lineup Sunday, the third straight day he was at least limited by left leg discomfort, but he pinch-hit for reliever Juan Nicasio in the sixth inning.
Polanco went through a full pregame workout, typically the last step before a player is cleared to return. He entered to face Kershaw with runners on first and second and two outs in the sixth inning and struck out swinging. He did not remain in the game to play defense.