Wayne Rooney suffered more frustration when Derby were denied victory by a stoppage-time goal which earned Coventry a late 1-1 Sky Bet Championship draw at Pride Park.
Colin Kazim-Richards' first goal for Derby looked to have given Rooney victory in his second match as interim manager but Gustavo Hamer fired home from the edge of the area to give Coventry a deserved point.
It leaves Derby without a home Championship win this season and they stay bottom of the table, four points adrift of safety.
Rooney reacted to Saturday's draw with Wycombe by making five changes but it was Coventry who came closest to taking an early lead.
Tyler Walker got down the Derby right in the 11th minute and whipped in a dangerous cross which Callum O'Hare just failed to connect with as he arrived at the back post.
It was 30 minutes before Derby created a chance with Kazim-Richards spinning away from a defender but he fired across Ben Wilson and wide.
A mistake by Matt Clarke three minutes later put O'Hare in but he stumbled as he went round Marshall and the ball rolled just wide.
Derby were getting into some threatening positions on the right and they had a great chance just before the break when a low cross was touched to Max Bird but his shot was too close to Wilson who turned it behind for a corner.
Both teams had shown plenty of intent and there were chances at either end at the start of the second half with Derby convinced they should have been awarded a penalty.
Kazim-Richards headed over a minute later but Coventry had a good chance just after the hour mark when O'Hare glanced a header just wide.
Derby's best moments came when they got the ball wide and when Jason Knight delivered from the right, Lawrence could not keep his shot down when the ball broke to him 15 yards out.
Coventry had headed well but a poor clearance in the 80th minute allowed Lawrence to shoot from the edge of the box but it was straight at Wilson.
Just when it seemed like Derby would again be frustrated, Kazim-Richards broke the deadlock in the 83rd minute when he squeezed a header past Wilson from Nathan Byrne's cross.
Jack Stretton should have finished it but hit the top of the crossbar and Coventry took advantage when Hamer drilled a low shot past Marshall after a cross was only half-cleared for a share of the spoils.