Leicester Tigers lock Will Spencer admitted he and his team-mates were "gutted" and felt that they had let themselves down after a disappointing loss to Worcester Warriors in the Gallagher Premiership season-opener for both sides at Sixways Stadium.
"We are pretty gutted ... I know it is the first week and we don't want to get too down but it's not up to the standards we set ourselves," Spencer told LTTV.
The Tigers second-rower paid tribute to his former club for their victory, but said the Leicester squad were their "own worst enemies" after a poor showing to begin the Premiership campaign.
"Credit to Worcester, they were better than us today," he said.
"We are so much better a team than we showed but, if you don't show it, it doesn't mean anything.
"We were our own worst enemies at times ... letting them go wave after wave of attack at us."
When pressed on specifics of what went wrong for Tigers, Spencer said: "It was simple stuff, non-negotiable in rugby."
"We could have easily won that game with 10-15 minutes to go.
"It's not good enough."
The Leicester lock was confident the changes made over the summer would still bring results and that the standards set would ultimately deliver the results required, no matter how pretty the rugby may be from the Tigers squad.
"We need to change the mentality," a visibly disappointed and frustrated Spencer said.
"We need to win those games, it's not always going to be pretty ... we just need to come away with wins.
"It's hugely disappointing, it's such small margins."
The second-rower also believed a "huge opportunity" was missed with the first up Premiership loss and the squad needed to regroup and do so quickly ahead of welcoming Saracens to Welford Road in Round 2 of the new league season.
"They were the better side today, but we don't believe they are a better side ... no disrespect to them," he said.
"We let ourselves down ... we are hurting today, that was a huge opportunity.
"We need to regroup and hopefully show the real Leicester next weekend."
Spencer added that while it was disappointing, a realistic approach was required so early on in the new season.
"Obviously we are pretty down now ... but we won't get ahead of ourselves, it is only week one," he told LTTV.
"We have to fix it fast, we have a huge challenge next week ... it's stuff that is within our control."
Welford Road will host its first Premiership fixture of the new Gallagher Premiership season on Sunday, October 27 and Spencer says the squad's focus remains returning the Leicester venue to a fortress for Tigers and an uncomfortable place for visitors to come.
"We love playing at Welford Road and have spoken about wanting to make it a fortress ... lets make it a very hard place for teams to come," he said.