Nationals released RHP Tyler Walker.
Nationals transferred RHP Tyler Walker from the 15-day disabled list to the 60-day disabled list.
Tyler Walker will undergo surgery on his right shoulder and has been ruled out for the rest of the 2010 season.
Tyler Walker (shoulder) has been shut down from throwing.
Tyler Walker (shoulder) threw a bullpen session Sunday for the first time since being placed on the 15-day disabled list on June 28.
Tyler Walker (shoulder) has yet to throw off a mound.
Nationals placed RHP Tyler Walker on the 15-day disabled list with right shoulder inflammation.
Tyler Walker was torched for six runs and eight hits in 1 2/3 innings out of the pen on Tuesday.
Nationals signed RHP Tyler Walker to a one-year, $650,000 contract.
The Nationals have signed RHP Tyler Walker to a one-year contract, pending a physical, according to FOXSports.com's Ken Rosenthal.
Phillies purchased the contract of RHP Tyler Walker from Triple-A Lehigh Valley.
Tyler Walker has accepted a minor league assignment, reports Todd Zolecki of MLB.com.
Phillies designated RHP Tyler Walker for assignment.