Experienced defender who started his career with Birmingham City progressing through the youth ranks there before making his debut in the Premier League.
He went on to make over 50 appearances for Blues before making a big money move to Watford.
Moved to Shrewsbury Town on loan in July 2010 and went onto make 46 appearances in a season long loan and became a big hit with Town fans.
After release from Watford he joined Walsall before a move to Crawley Town.
Spent the 2014/15 season with Rotherham in the Championship but didn't get a first team chance and spent time on loan at Crawley and then Oldham.
Sadler signed for Town in the Summer of 2015 on a two year deal.
After struggling to hold down a regular first team spot for most of the campaign, Sadler’s experience was vital towards the end of the season as he replaced Junior Brown for the final few games to guide Town to safety.