PETER JACKSON pulled no punches after watching Town concede two goals for the first time in pre-season over at Spotland.
Town needed a brilliant Andy Booth header and a Pawel Abbott penalty to twice come from behind after Rickie Lambert and Grant Holt fired Steve Parkin's League II battlers ahead.
"That's probably the worst we've defended in pre-season," admitted the manager.
"The centre-backs were at sevens and threes and we've got to be a lot tighter at Forest on Saturday.
"We didn't win the play-offs or finish last season with eight wins out of nine by giving away silly goals, so we have to get back to basics and start keeping clean sheets.
"If we do that we'll be fine, because our fitness and our general play is good and I'm confident we'll score goals, but defensively we still have some work to do."
There was little Town could do to stop the ninth-minute free-kick opener from 25 yards of Rickie Lambert, who is arguably the best dead-ball specialist in the lower divisions.
But the second Rochdale goal was a simple punt down field which Nathan Clarke would normally have cleared into row Z.
Instead, he allowed Holt to rob him of possession and, with a clear run to goal, the striker beat Paul Rachubka with a fierce cross shot.
That was four minutes into the second half and restored Rochdale's goal advantage which had been wiped out on 17 minutes by a towering Booth header from Danny Adams' free-kick.
Town were again on level terms quite quickly when, from a 54th-minute raid, Rochdale wingman Tommy Jaczczun clearly pulled back Andy Holdsworth by the shirt in the box.
Referee Michael Ryan had no hesitation and Abbott, who had a penalty saved by Kevin Pressman in the senior friendly at Mansfield, this time made no mistake, firing low and firmly to keeper Matthew Gilks' left.
While Town looked lively with breaks from midfield by Mark Hudson - who fired over on 22 minutes from a flowing move - Abbott and Chris Brandon, and there was lots of hard graft from the skipper, Jon Worthington, they were indebted to two marvellous saves by Rachubka to finish even.
The first came after 35 minutes when Holt was played clean through - Rachubka diving full length to palm the ball around his right hand post - and the second seven minutes from time when substitute Blair Sturrock again escaped the defence.
"We played some decent stuff going forward and were rewarded by an excellent header from Boothy and a solid penalty from Pav," reflected Jackson.
"The lads created some chances which need to be tucked away, but the biggest area we need to look at is the defence, because we can't afford to let teams get through us so easily.
"Particularly the second goal, when Nathan let them in, was a bad one to concede, but Clarkey has been out for a week and a half and I think it showed. He looked a little bit rusty and short of match practice."
Rochdale - Gilks, Clarke, Gallimore, Brisco, Griffiths, Boardman, Cartwright, Jones, Holt (Tait 83), Lambert (Sturrock 77), Jaczczun (Kitchen 67).
Town - Rachubka, Holdsworth (T Clarke 76), Adams, Hudson (Collins 80), Mirfin, N Clarke, Brandon (Taylor-Fletcher 71), McIntosh, Abbott (Schofield 71), Booth, Worthington. Sub not used: Eastwood.
Referee - Michael Ryan.
Attendance - 1,903 (including 500 from Town).