Fremont Councilmember Vinnie Bacon suffered a concussion following an accident while riding his bike last Monday.

Bacon, who is one of potentially five candidates interested in replacing long-time Alameda County Supervisor Scott Haggerty next March, said he did not sustain any other injuries.

The circumstances of the accident is unclear. But because he was concussed, Bacon spent the night in the hospital as a precaution, he wrote.

“For those who didn’t hear I got in a pretty gnarly accident on my bike last night,” Bacon wrote on Facebook late Tuesday night. “I look absolutely horrible right now but I toughed it out through a long Council meeting.”

Bacon is going to need to mend quickly. The race for Haggerty’s District 1 seat is a wide-open after the incumbent announced last May that he would not seek re-election after more than two decades in office.

Of the current potential field, Bacon’s campaign has been in operation the longest. When he announced his run for supervisor last February, he initially intended to challenge the incumbent Haggerty.

State Sen. Bob Wieckowski, Dublin Mayor David Haubert, Dublin Melissa Hernández have also filed intent to run for the seat. Former Dublin Mayor Tim Sbranti is also rumored to be interested in the seat that represents Fremont, Sunol, Dublin, and Livermore on the Board of Supervisors.