Buchanan, who is not on the 40-man roster, is slated to start Sunday for Lehigh Valley.
Cole Hamels, recovering from biceps tendinitis, allowed one run and six hits in six innings while making a rehab start for Clearwater at Lakeland on Saturday. Hamels threw 67 pitches, 48 for strikes.
This was expected to be his next-to-last rehab start. If that is the case, Hamels could join the Phillies April 22 in Los Angeles.
Revere still out
Tony Gwynn Jr. started in center field for the second straight night in place of Ben Revere, who has a sore rib. Revere pinch-hit and grounded out Friday night in a 6-3 win over the Marlins.
"Ben is still a little tender, so we will give him another day to see how he feels," Sandberg said.
Lincoln sent down
To make room on the 25-man roster for Jonathan Pettibone, Saturday's starter, the Phillies outrighted reliever Brad Lincoln to Lehigh Valley.
In two games for the Phillies covering 21/3 innings, Lincoln gave up three earned runs.
Sandberg said Lincoln is going down to Lehigh Valley with instructions to work on a two-seam fastball to complement his four-seamer.
A breather for Diekman
Lefthander Jake Diekman, who appeared in seven of the first 10 games, including three in a row, said before the game he would be ready for action. "I feel I can pitch," Diekman said.
Sandberg said he would give Diekman the night off.
Diekman had pitched 22/3 innings the previous three games but threw just 33 pitches, 24 for strikes.
Reliever B.J. Rosenberg, who wasn't available Friday because of neck tightness, entered Saturday's game in the 10th inning.
Phillies reliever Mike Adams allowed one run on two hits in one inning for Lehigh Valley on Saturday against visiting Rochester. Recovering from right shoulder surgery, he threw 21 pitches, 14 for strikes.
Former Phils reliever Rheal Cormier, who had the first win at Citizens Bank Park, threw out the first ball. Saturday was the 10th anniversary of the first major-league game played there.