Manship, 29, has a 6.42 ERA in 52 career games. O'Sullivan, 26, has a 5.89 ERA in 50 career games. Buchanan, 24, was the last internal player invited to camp. He posted a 4.40 ERA last season between double-A Reading and triple-A Lehigh Valley.
"O'Sullivan is a guy," Sandberg said. "We have Manship. We have Buchanan. It just creates an opportunity for somebody to continue through camp. I'll observe everybody."
Both Sandberg and Ruben Amaro Jr. excluded Cuban import Miguel Alfredo Gonzalez from their list of options. When asked if the 27-year-old righthander - signed to a three-year, $12 million contract last August - was an option for April, Amaro said, "He could be."
"I'm watching him," Sandberg said. "Yeah."
Gonzalez and Buchanan were scheduled to pitch Thursday against Detroit, a game canceled by rain. Pitching coach Bob McClure waited until Friday morning to formulate a new plan.
Amaro said it would be difficult to find an external option better than the team's current hand.
"If you talk to 30 GMs right now, they're all looking for pitching depth," Amaro said. "We'll keep looking. There may be some guys with out [clauses], there may be some guys who may be available who don't have options."
Minnesota's situation is one to monitor. The Twins have three pitchers - Vance Worley, Scott Diamond, and Samuel Deduno - who are out of options and competing for one rotation spot. Worley, 26, made 46 starts for the Phils before being traded to the Twins in December 2012.
Long wait for loss
The other half of the Phillies' split squad waited 86 minutes for severe storms - including a tornado warning - to pass Bright House Field. Freddy Galvis crushed a solo homer off Japanese sensation Masahiro Tanaka, but the Yankees won, 4-3.
Kyle Kendrick allowed one run in three innings. He rolled four groundouts and struck out two but permitted a home run to Ramon Flores.
"This time, I just wanted be more aggressive," Kendrick said.
This was the first chance for Sandberg to test baseball's new instant replay rules. He challenged a play at first base in the sixth inning. The play was upheld. A call at third in the seventh inning was reviewed, but the stadium lost power briefly before the play and the replay loop was not captured. . . . Mario Hollands allowed one hit - a Derek Jeter double - in two scoreless innings. "He's been a pleasant surprise," McClure said. "His two innings were a bright spot today."
Columnist Bob Ford contributed to this article.