Head coach Shaun Derry left Cambridge three minutes after their 0-0 draw with Lincoln.Derry leaves by mutual consent with the team 14th in League Two, having been with the U's since November 2015.Barry Corr flicked Jevani Brown's cross wide for Cambridge early on and from then the Imps enjoyed the best of the first half.David Forde came out to save at the feet of Matt Green, before Matt Rhead's knockdown was turned wide by Harry Anderson from close range after 15 minutes.Anderson also saw a goal disallowed for offside, before on the stroke of half-time Rhead headed Sam Habergham's cross wide from beyond the far post.Cambridge substitute David Amoo raced down the right and saw his low effort well saved by Ryan Allsop after 64 minutes.With 18 minutes remaining Allsop made a terrific stop to turn Corr's header's wide after Amoo's cross. A Corr header was ruled out because of an offside flag as both sides searched in vain for a winner.