Butler, 33, will not be offered a new deal by the Saddlers when his contract expires at the end of the season so has been made available for a move now.

He rejected a switch to Peterborough before the transfer window closed in August after the clubs agreed a fee.

The former Reading and Rotherham man has scored 13 goals, including one this season, in 53 appearances for Walsall since joining the club in May 2006.