BALTIMORE -- Clay Buchholz won't be starting either game of Tuesday's doubleheader, and the right-hander could be headed to the disabled list.
Manager John Farrell said that Buchholz is still battling problems in his trapezius muscle. There's been some improvement, but he isn't ready to pitch in a game.
"Clay threw today and feels a little bit better than he did yesterday," Farrell said, "but not to the point where he's going to throw a bullpen [session] tomorrow. We do have the benefit of the off-day [Monday] where we can keep guys on turn with Felix [Doubront] going on Tuesday, [Ryan] Dempster on Wednesday and stay on turn from there. Right now, we haven't announced the other starter for Tuesday."
After Boston's 5-4 win Saturday, Buchholz said he's getting better every day but is trying to be careful.
"That's why I told them. There's no need to schedule anything [like a bullpen session]," he said. "Whenever I feel I'm ready to get off the mound, I'm going to get off the mound."
The right-hander said now it's just about the trapezius muscle and not the AC joint. Buchholz said he wants to avoid the DL, but if that happens, the Red Sox could make it retroactive to June 9 and limit his stay there.
"From the beginning, I really wasn't worried about it being something that was going to take a really long time, but it's definitely going to take longer than I want it to take," he said. "I'm trying to be as smart as I can with it and keeping everyone in the loop with how it feels, the progression each day, and that's where we're at right now. I'm making progress every day. There's no reason to take a step backwards if I don't have to."
If Buchholz doesn't improve by Tuesday, the Red Sox will need to decide on a possible roster move, said Farrell.
If so, then Boston will need a starter for later in the week against Detroit.
"So we've got a couple of moving parts right now," Farrell said.
As for now, the Sox need to find another starter for Tuesday's twin bill vs. the Rays. It appears that Rubby De La Rosa and Alfredo Aceves are the two main choices for that contest.
Part of that decision is going to be affected by De La Rosa's workload. He was called up Friday and hasn't pitched since throwing five innings for Triple-A Pawtucket on June 8.
Feeling ill, Napoli back in Boston undergoing tests
BALTIMORE -- Mike Napoli was sent back to Boston on Saturday for tests to see if the Red Sox can find an answer to the puzzling illness that's bugged him the past few days.
Following a 5-4 win over the Orioles, manager John Farrell described Napoli's situation as "general illness." The Sox have gotten preliminary tests completed, but Farrell didn't have results and they're still hoping to find out what's making Napoli ill.
"We've got a virus running through the club," Farrell said prior to the game. "We had a couple of guys throwing up yesterday that still played, but because this is persistent since the other night, we want to be sure that he's in a safe place, and we can get to the bottom of it."
The Red Sox had to pull Napoli in the third inning of Thursday's loss to the Orioles due to the dizziness, nausea and light-headedness. It improved a little in the past two days, but Boston's looking for answers.
Farrell said the team's pretty sure this is not concussion-related, but they don't have the final answer just yet.
"He's going to see our internist and then any kind of recommendation they'll make for follow-up, he'll do," Farrell said.
With game on line, Nava delivering in clutch situations
BALTIMORE -- Daniel Nava came into Saturday's game with the Orioles in the midst of a very productive season. The switch-hitter wasn't in the starting lineup, but he had nine homers and 44 RBIs in 62 games.
The 30-year-old leads American League outfielders in at-bats/RBI ratio (4.95), but Nava's also first in RBIs late in the game. Nava's knocked in 24 of his 44 runs from the seventh inning or later, tops in the Major Leagues.
Nava said he's just gotten a lot of chances late in games to be up at the right times, and he's taken advantage of it.
"We have a lineup that works at-bats, and later in the games, that stuff pays off and it's paid off to have guys on base," Nava said. "Fortunately, I've been the guy up to have an opportunity to get that knock."
Later in games, Nava works on keeping things rather simple. He doesn't go complex, especially when coming to the plate with runners on base.
And so far, that's been working well.
"I'm just trying to get a good pitch to hit," Nava said. "I know it's a plastic saying, but I think when the game gets on the line, I think every [player says] he tries to simplify things. Simply for me means look for a good pitch and not worry too much about the result, but really try and focus on the process."
• Farrell said Will Middlebrooks has been taking some grounders at first base in case Boston needs some help. The skipper said the Red Sox are adjusting as they go due to all the injuries.
• Dustin Pedroia saw his season-best 22-game on-base streak come to an end in Friday's 2-0 loss to the Orioles. He's reached safely in 63 games so far this season and has started all 70 contests.
• Friday's shutout was just the fourth time the Red Sox have been blanked so far in 2013. Boston still leads the Major Leagues with 355 runs and 349 RBIs.
Jeff Seidel is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.