Riggleman did not know how many innings Zimmermann would pitch during the season. The skipper needs to talk to pitching coach Steve McCatty and pitching coordinator Spin Williams before announcing the number of innings.
Zimmermann returned to the Nationals in late August, after having ligament-replacement surgery on his right elbow in 2009. He pitched in seven games and allowed 17 earned runs in 31 innings. He also averaged 7.8 strikeouts per 9.0 innings.
"We are not looking for Jordan to go out there give us 200 innings or anything like that this year. That is more for the future," Riggleman said. "But we do want him to go out there and be a stabilizer."
Zimmermann will be one of seven pitchers looking to fill spots in the rotation. Riggleman said it's not yet known who will follow Livan Hernandez in the rotation.