Sen. Robert Byrd, D-W.Va., is still undergoing physical therapy and is not expected to be released this week, according to a new release issued Monday.

It is expected that Senator Patty Murray (D-WA) will manage consideration and debate on the FY 2010 Homeland Security Appropriations bill when it comes before the full Senate later this week, the release said.

Byrd is resuming some of his official duties while recuperating, including signing several enrolled bills as President pro tempore of the Senate, and working with staff on upcoming appropriations bills, the release said.

Byrd was taken to an undisclosed hospital May 15 after developing what his staff said was a minor infection. He developed a more serious staph infection while in the hospital and was treated with antibiotics.