Sen. Tim Johnson (D), expected to cruise to re-election this fall, announced on Friday that he will not participate in any debates with his GOP challenger, state Rep. Joel Dykstra.

Dykstra said last week that he had accepted an invitation by a South Dakota TV station to debate Johnson at a televised, hourlong event on Oct. 21.

Johnson suffered a brain aneurysm on Dec. 13, 2006, and was away from the Senate for the next nine months as he recovered from his illness. He returned to work last September.

“I have been open and honest about my recovery,” Johnson said in a statement. “While my speech continues to improve it is not yet 100 percent and I have not yet reached a point in my rehab where my participation in a debate would accurately reflect my capabilities. Therefore I will not participate in traditional political debates during this campaign.”