Concentrating on expanding his repertoire as he goes back to the rotation, Papelbon threw several curveballs along with his fastball and splitter among his 62 pitches (42 for strikes).
"It feels really good," Papelbon said of his curveball. "I'm just working on throwing it in certain counts, 1-and-1, 1-and-0, and building it to where I can throw it in any count. That's going to be a big part of my success this year and it's something me and [pitching coach] John Farrell worked on today.
"You have to be able to throw other pitches for strikes in any count, and that's the point I want to get at. Hopefully, it gets where it needs to be. That's the big difference [in starting]. You're having to go deeper into games. You're having to throw more strikes and keep hitters on their toes."
Papelbon knows that a consistent curveball will be a key to his success.
"Even if you throw it for a ball, you're still going to have to use that pitch successfully for your next pitch," he said. "For me, my curveball is going to be huge. That's the reason they had me down here, to work on it.
"You need that torque. When you finish that pitch, you have to have that torque coming through at full speed. You can't throw a curve and lollygag it in there. A curveball has to be a pitch that has touch and feel, yet at the same time, you're throwing it at full velocity."
In his second inning, Papelbon gave up home runs to Chris Durbin and Eric Crozier. Both round-trippers came on fastballs.
"It was a little weird," Papelbon said of the simulated game, held at the Minor League complex two miles east of City of Palms Park on Edison Avenue. "You have to get fired up a little bit more to get up. Nothing to take away from these guys, they're working really hard. I took today and worked on a couple things, like my curveball, a lot. I had one inning where I fell behind some hitters and wasn't successful. But I got good work in. So I'm excited about that."
Manager Terry Francona was satisfied with Papelbon's outing.
"We needed to get him some work," Francona said. "A simulated-type game on Field 1 at the complex isn't perfect, but it did what we needed to do. It got to 62 pitches. He had a tough second inning. He didn't locate his fastball real well. We got out of it what we needed to.
"Working on the curve, having a third pitch as a starter [is important]. You go through that lineup a third time and sometimes the swing and misses become foul balls. Even if they're not scoring runs, the pitch count goes up. Certainly, if he can add the third pitch, it certainly helps being economical going through a batting order."
"The breaking ball is a little bit more of a feel pitch," Francona said. "He's going to have to throw it. His arm slot is so conducive for his split and his fastball with the deception and power. The breaking ball, he can get under it a little bit.
"How many curves [he'll throw] a game, I don't know. That's something we don't know. We haven't seen him as a starter."
The last time Papelbon started was in 2005, when he made a combined 21 starts at three levels -- 14 starts in Double-A Portland, four in Triple-A Pawtucket and three with the Red Sox.
"I thought it was a pretty good pitch for him at that time," said Pawtucket pitching coach Mike Griffin of Papelbon's 12-to-6 curveball. "I saw an above-average Major League curveball. I thought it had good depth. Some of his curveballs had good rotation to them. I think it's a very effective pitch for him.
"It was his third pitch. He would throw it early in the count, throw it for a first-pitch strike, getting ahead in the count. It's not his out pitch. That would be the fastball and the splitter. He used the curveball to get hitters off his fastball."
Moving on: The Sox made five roster moves Monday, reducing the Major League Spring Training roster to 47 players.
Right-hander Nick Debarr, a Rule 5 Draft pick in December, was returned to the Devil Rays, right-hander Kyle Jackson was optioned to Double-A Portland and three non-roster invitees, left-hander Abe Alvarez, catcher Dusty Brown and outfielder Kerry Robinson, were assigned to Minor League camp.
"There wasn't room," Francona said of Debarr, whom the Sox would have been required to keep on the 25-man roster for a full season. "I understand why he was a Rule 5 guy. He's a guy with a pretty good arm. And for the money you're paying pitchers, it's well worth look. But, it was going to be virtually impossible for him to make the team. Rather than string him along, we offered him back."
Debarr was 4-3 with a 2.74 ERA in 40 games with Class A Visalia in 2006 after missing all of 2005 rehabbing from ligament reconstruction surgery on his right elbow. He had made just one appearance, for an inning of work, in a Major League game this spring.
"It was just a great opportunity," Debarr said of his time in Sox camp. "I just have good things to say about what happened. It would have been nice to have a little bit more of a chance to show them what I can do. My appearances and innings were kind of limited. ... For them to even think of me maybe helping their team has been great."
Running on: Francona said while he would like to see Coco Crisp and possibly Julio Lugo stealing bases this season, he wants to be sure it is in the right situations.
"As much as [Crisp] can be safe, he can run all he wants," Francona said. "But we need him to be safe. That's what we tell all our guys. Even with Lugo running, great. We just don't want to make outs. If guys are good enough base stealers and they're smart enough to run at times, that's a wonderful aspect of the game. We just don't want to leave our good hitters standing in the batters' box.
"I'd say 80 percent [success rate] is good. There are times when maybe get to the bottom of the order, maybe you want to take a shot with two outs. It may be different, but we really value our outs. That's probably the best way to put it."
With a career-high 22 stolen bases in 26 attempts in 2006, Crisp had and 85 percent success rate. Lugo combined for 24 swipes last season between the Devil Rays and Dodgers, a 73 percent success rate.
Honoring Vuk: Francona, bench coach Brad Mills and pitcher Curt Schilling will fly to New Jersey on Tuesday morning in team owner John Henry's private jet for the funeral of John Vukovich. The former Phillies player and coach died Thursday at the age of 59 from complications related to a brain tumor.
Schilling is expected to pitch in a simulated game Tuesday night at City of Palms Park. The game will be the equivalent of five innings pitched and will not be open to the public.
Up next: The Red Sox head to Dunedin, Fla., on Tuesday to face the Blue Jays at 1:05 p.m. ET. Kyle Snyder is scheduled to start, followed by Bryan Corey.
Maureen Mullen is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.