Judoka Sally Conway has admitted the British squad lacks strength in depth after a fourth day without a medal at the World Championships in France.
The 24-year-old's contest in the -70kg division lasted less than two minutes as she lost to Slovenia's Rasa Sraka.
Two-time Olympian Winston Gordon won his first -90kg fight but was beaten by Ivan Remarenco of Moldova.
"Britain hasn't got depth [in the squad]. We will come through, but it takes longer," Conway told BBC Sport.
"Japan and France have a lot of depth and a lot of good players coming through. They've always got someone behind them, they've always got people to rotate."
Asked whether Britain should be concerned by their lack of squad strength less than a year before the 2012 Olympics, Conway replied: "I don't think so. You train with what you've got and you have to believe your best will be good enough."
The day began in all too similar a vein for Britain, as Gordon got the team off to a winning start when he forced Panama's Rene De Urriola into submission with an arm-lock to win by ippon, the perfect score.
But he struggled to grip Remarenco in his second bout, which he lost in golden score (over-time) by submitting to an arm-lock.
"I don't think the British squad is struggling, it's a strong event," Gordon told BBC Sport. "There are world champions and Olympic champions out there who are losing in the first round, everybody's struggling.
"With the work the team's been doing, I think we'll be ready [for the Olympics] and do well."
Colin Oates' fifth-place finish in the -66kg category is the best result GB have managed in a competition they have not won since 2005.
Edinburgh-based judoka Conway struggled to match Sraka and submitted via arm-lock.
Conway, who has recently recovered from a lengthy wrist injury, said: "I think getting here was a big step for me. Today wasn't my day, I'll have to go back to training and work on some tactics."
In Saturday's competition, the concluding day of the individual championships, James Austin (-100kg), Sarah Adlington and Karina Bryant (+78kg) take to the mat for GB.
Follow Olympic sport reporter Jessica Creighton on Twitter for updates throughout the championships.