Scherzer said he wants to be sure he is at 100 percent. He recalled that while at the University of Missouri, he had a cut in his right middle finger and pitched through the pain. Two weeks later, he had biceps tendinitis.
"I almost really messed up my shoulder," Scherzer said. "I really respect the fact that you have to be 100 percent to go out there. In this case, that's how I'm going to treat it. I'm showing progress every single day. I'm happy where it's come, but I'm literally day to day. It's hard for me to give anything beyond a few hours at a time."
Scherzer hurt the thumb against the Cardinals on Thursday while in the batter's box. The swelling increased the next day, and the thumb was treated with anti-inflammatory medicine.
During the throwing session, Scherzer said he was able to grip the ball better than he had anticipated.
"I'm dealing with a little sprain in there," he said. "For me, it's just doing treatments and see where this goes."
Like Scherzer, Cardinals ace Adam Wainwright was hurt in the batter's box, sustaining potentially season-ending injuries to his left Achilles and ankle on a popup on Saturday in Milwaukee, prompting the Nationals righty to suggest the use of the designated hitter in both leagues, according to CBS Sports.
"I wouldn't be opposed," Scherzer said in the interview.
Scherzer spent the previous five season in the American League with Detroit before signing with the Nationals in the offseason.
"If you look at it from the macro side, who'd people rather see hit -- Big Papi or me?" Scherzer told CBS Sports. "Who would people rather see, a real hitter hitting home runs or a pitcher swinging a wet newspaper? Both leagues need to be on the same set of rules."
Scherzer is 1-for-9 with three strikeouts at the plate this season.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.