Valdez isn't in the lineup for Thursday's game against the White Sox.
The Pirates recalled Kelly from Triple-A Indianapolis on Thursday.
The Pirates placed Ashcraft on the 15-day injured list Thursday with right arm discomfort, retroactive to Monday.
Siri went 2-for-4 with a two-run home run in a 6-4 win over the Red Sox on Wednesday.
Guzman went 3-for-4 with a solo home run and an additional run scored Wednesday in a 6-4 victory over Boston.
Montgomery got the save Wednesday against the White Sox, striking out two in a scoreless ninth inning.
Griffin went 1-for-4 with two RBI and two stolen bases Wednesday in the 4-2 win over the White Sox.
Valdez went 1-for-2 with a solo home run in the win Wednesday against the White Sox.
Johnson (4-8) notched the win against the Red Sox on Wednesday, allowing three runs on five hits and one walk in six innings. He struck out five.
Neto went 2-for-3 with a three-run home run in Wednesday's 6-4 win over Boston.
