Ian Evatt lamented more missed chances as Wanderers saw their play-off hopes hit by a first home defeat since January.
Plymouth hung onto their top-six spot thanks to a 1-0 victory as the Whites were beaten at the University of Bolton Stadium for the first time in eight games.
The loss left Evatt’s 11th in the League One table and 10 points away from the play-off zone.
And Evatt pointed to wasted opportunities in front of goal as the key as his side ended a frustrating week with just one point to show from impressive performances against Morecambe and Argyle.
“The two games we’ve had, we had enough chances to win many games and we just haven’t taken them,” said the Wanderers’ boss.
“The last two games I feel we’ve played really well and we’ve come away with one point and I’m scratching my head as to how.
“Plymouth are a really good team. They rode their luck and probably earned that bit of luck with how they’ve performed this season. But we’ve let them off the hook.
“The keeper’s made some great saves but he shouldn’t be given an opportunity to save them.”
Evatt added: “I’m really frustrated because we did a lot right again against a really good team.
“We controlled the game – other than a 15-minute spell at the end of the first half when they didn’t really hurt us but we’ve lost the game on a set-play. That’s the importance of set-plays.
“In the first half we had so many great opportunities where we had overloads but we looked timid and lacking confidence up front.
“You have to have a belief about scoring and if you miss a chance, that’s fine, you make sure you get the next one.
“As a defender, when your forwards are missing chances you then become nervous and worried that one mistake will cost you the game. We can’t have that.
“I keep saying it, we win or we learn and again we’ve learned today that we’re a good team and we’re doing a lot of things right but we have to be more ruthless in front of goal. “
Wanderers have just eight games left to pull off the improbable as they lost further ground in the play-off race.
But Evatt will demand no letting up on the back of a season of progress following promotion last year.
“The way we are playing is great and if it’s not this year, then we have to finish strong and improve for next year,” he said.
“Things are looking up for us. We’re obviously going to be disappointed because we want it now and I’m the biggest one for that.
“But sometimes it’s about just improving and working hard on some foundations for the future and I think what we’ve done this season is certainly build those.”
Wanderers finished against Argyle with 10 men after Marlon Fossey limped off near the end and the on-loan Fulham man will be assessed next week.
“He’s got a few twinges in his knee. We’ll have to see how that settles,” said Evatt.