Canterbury coach Trent Barrett was left disappointed with a few basic areas that played into Penrith's hands but otherwise saw patches of improvement during the side's 28-0 loss on Saturday.
The Bulldogs were kept scoreless by last year's minor premiers during an 80-minute slugfest in torrential conditions but were their own worst enemy with the ball in hand.
A disallowed team try was briefly one of the few highlights for the home side, who were eventually overrun by a more controlled Panthers side which came up with five unanswered tries.
"I'm seeing improvement but not for long enough periods," Barrett said.
"That's the big thing, to beat the good sides you have to play for 80 minutes and we're patchy.
Match Highlights: Bulldogs v Panthers
"There are periods in the game we're really competing for long periods. To go at 4-0 for a long time and then 10-0, could have been another try our way, but ultimately, it'll wear you down.
"The two forward passes from dummy half, a couple of yardage errors again, it just puts too much pressure on your defence but ultimately you get what we got.
"Last week we probably had a really good 20 minutes, tonight we had a really good 40 minutes but the game goes for 80 and we're getting found out through tough periods of the game."
Watene-Zelezniak sent to sin bin for high tackle on Cleary
Bulldogs winger Dallin Watene-Zelezniak was placed on report for a high tackle on Panthers halfback Nathan Cleary that could come under scrutiny with the match review committee.
"He's hung his arm out there and got him high, but I don't think it was intentional," Barrett said.
"It was a difficult tackle to make. Hopefully he [Cleary] is all right."
After narrowly avoiding the wooden spoon last year, Barrett's tenure at the club has started shakily despite a host of new recruits that brought optimism in the off-season.
The Bulldogs will travel to Brisbane next week for a clash with the Broncos before the following fortnight reads South Sydney and Melbourne.
"We've got to go to Brisbane next week with a good attitude and get a win," Barrett said.
"Next week is really important, Brisbane are in a similar position, losing their two opening rounds.
"I can't look any further ahead than that. This is not about the ultimate outcome, there's a process here that we need to go through to fix the patches in our game that aren't up to scratch.
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"The minute I start looking that far ahead I'll lose focus on what we need to fix.
"My job is to keep improving. I've got to stay positive with the group, there's no magic fix for it. It is what it is. There's no easy fix here."
Barrett could be without Raymond Faitala-Mariner (ankle) after the second-rower forward failed to finish the game in the first half.