"We know he's not going to be ready for the next series," Nats manager says.
"I’m bored out of my mind. I’m ready to start playing," said the outfielder.
Injuries derailed the Nationals' 2015 season, and it mostly began in spring training.
Ross said he is feeling better already and will be re-evaluated on Monday.
Ryan Zimmerman ran with a team physiotherapist, part of the Nationals' efforts to build him up for the season.
Jayson Werth: "You’ve got to find a way to win. You’ve got to find a way to overcome it. We’re in it right now."
Also, a quick note on why Bryce Harper took on-field batting practice before the first game of the Pirates series.
Werth is able to swing a fungo bat as he works his way back from a wrist injury and remains on target for a potential return in August. Plus updates on Aaron Barrett, Anthony Rendon and Ryan Zimmerman.
The left-handed starter faced four teammates and simulated three innings on Sunday morning.
The Nats are hoping for good news, but the second opinion is usually a precursor to Tommy John surgery.