Who is the democrat Senator that is not able to participate/vote due to illness?

Question

I believe I heard he won't be able to participate for some reason ( can't remember) and that it takes the VP to break a tie.

Answer 1

senator Tim Johnson(SD) Democrat , Weeks after suffering a brain hemorrhage, Sen. Tim Johnson is improving but still needs a ventilator at night to help him breathe, his doctor said Wednesday.
his long-term prognosis is unclear. and perhaps his recovery is expected to take several months.
If yon wana know more about him visit : http://johnson.senate.gov/about.html

Answer 2

Senator Johnson (D-SD) is currently still in the hostipal after brain surgery in December. He is expected to fully recover.