McLouth was a late scratch for Sunday's game with patellar tendinitis in his left knee. He had stepped wrong and it "fired up pretty good" during batting practice.
"There's a lot of ground to cover," McLouth said about Marlins Park. "We took batting practice early this afternoon and I was running around, and it felt pretty good. I'm pretty confident."
• Tests confirmed that third baseman Ryan Zimmerman's thumb would not require surgery. The timetable for his return remains 4-to-6 weeks.
"The bone is in place. It's fractured, but it's in place," Williams said. "That's a good thing, that there's no surgery or invasive things that need to be done. So he's just healing up. Bones take time."
• Catcher Wilson Ramos had the stitches taken out of his left hand, starting the rehabilitation process following surgery to remove the hamate bone. Ramos has been working on his fitness at home to stay in shape.
"All indications are he's well on the road to recovery," Williams said.
• Right-hander Doug Fister, who threw 50 pitches in a bullpen session on Monday, will not throw in a simulated game until the club returns to Washington.
"Heavy dose he got yesterday, it'll be a couple days before he does anything anyway," Williams said.
Christina De Nicola is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.