Gary Brabin was left frustrated as Vale's Carabao Cup campaign came to an end at the earliest possible stage on Tuesday evening, with Lincoln City running out 4-0 victors at Vale Park.
An early Jason Shackell header separated the two teams at half-time, but the Valiants went on to ship another three goals during a frustrating final 45 minutes that saw the visitors profit.
Despite admitting that the scoreline was slightly flattering for Lincoln, Brabin insists that the Vale squad must become sterner and rid of the 'soft underbelly' that has seen them fail to capitalise on the opening day victory over Cambridge United.
He said: "We know the last two performances and results have certainly not been what we expected. We still think there is some good in there, but unfortunately we are showing a real soft underbelly which needs to be ironed out quickly.
"There are certain things which we have said to individuals, and what we are thinking collectively, which we don't really want to say too much at the moment.
"You can definitely tell on everyone's face that we are disappointed. We expected a better showing than we have shown in the last two games, certainly after what we displayed we are capable of in the first game.
"We have created chances today, we got crosses into the box and hit the bar. At 2-0 down we seemed to start playing and we created a few opportunities. We just needed that goal to get back into the game, but then you concede the goals we have conceded - not just the first two, but the two after.
"That was after we had showed a little bit more spirit to get back into the game. To concede another two goals like we did has alarmed us and we need to make sure we improve quickly."
One player who was unable to feature for Vale was the prolific figure of Tom Pope, with the striker limping off with an injury during last weekend's league meeting at Colchester United.
Louis Dodds replaced him in what was his first start since returning to Burslem, but he and the rest of the players were unable to find the net. Antony Kay did hit the crossbar and Luke Hannant forced Grant Smith into a superb save, but it wasn't to be.
Despite the lack of goals, Brabin believes there is enough quality in the group to improve at both ends of the pitch, and he is expecting a much better showing this weekend when Crawley Town make the trip to Vale Park in Sky Bet League Two.
He said: "There is more to it than Tom Pope. Last year we relied heavily on him, but that can't be the case this time around. We believe we have enough quality in there, but it has to start happening quickly.
"We are certainly disappointed with some individuals, you can forgive one bad performance, but to have two on the spin isn't good enough and won't be accepted.
"We do feel like we have played against two of the better sides in the league (Colchester and Lincoln), but that should be a benchmark for us to show what we are capable of.
"The lads showed we are capable of being a good side in the first game of the season, but then to perform like we have done against two of the better sides - the goals we have conceded were poor and it is not good enough."