Holland's fastball actually had more zip on Monday during a rough outing in which all five Brewers he faced reached base.
"I think his velocity has been OK," Yost said. "He hasn't exhibited the 97-mph fastball but he was 94-95 [Monday] night and that's fine by me."
Why would Holland, 29, suddenly have a decrease in velocity?
"He's getting a little older," Yost said. "Just because you throw 97 one year doesn't mean you're going to throw 97 your whole career.
"But the thing that he's got is ... huge cojones. And he can locate, and he's got great stuff. He doesn't need a 97-mph fastball. He's got grit and determination, and along with his stuff, that makes him invaluable."
Vargas doing better
Left-hander Jason Vargas, who is on the 15-day disabled list because of a left flexor strain, played catch on Tuesday and said his forearm was feeling much better.
"The inflammation in there seems to be down," Vargas said. "Have a little more flexibility."
The next step will be for Vargas to throw a side session in a few days. Vargas will be eligible to come off the DL on June 24. Yost doesn't expect Vargas will need any rehab starts in the Minors.
Jeffrey Flanagan is a reporter for MLB.com. Follow him on Twitter at @FlannyMLB. This story was not subject to the approval of Major League Baseball or its clubs.