Doncaster Knights dropped out of the Championship’s top four following Sunday’s 35-26 defeat by Cornish Pirates at Castle Park.
A last-minute penalty robbed them of a losing bonus point which allowed Nottingham, held to a 19-19 draw by Rotherham. to claim fourth spot.
“Our lack of discipline proved costly in the second half – especially at the end when we finished up with just one point when we looked to have two in the bag,” said forwards coach Glen Kenworthy.
“It was disappointing to lose the game after scoring four tries to their three, but at the end of the day we just weren’t good enough.
“They are a good team but they didn’t do anything we’d not identified and talked about in the build-up.
“They aren’t a flash team but they roll their sleeves up and get stuck in and if you aren’t on your game, or if you make the sort of daft decisions at the wrong time as we did, then they will punish you.”
He added: “We came in 18-5 down at the interval and although we hadn’t played well we felt we were still in the game, which we were when we got it back to 18-12. We put them under further pressure but we couldn’t get the third try we wanted at that stage.
“Once again they capitalised on our discipline and they kicked three penalties to pull well clear again.
“We gave ourselves an outside chance but we let them in for a diabolical try.
“I don’t really know what happened but we seemed to stand off them for some reason at a ruck.
“We’ve certainly got some work to do this week ahead of Jersey.”