Luke Charteris hit out at Wales after they suffered a 40-7 defeat to Chiefs in Tuesday's tour match in New Zealand.
Having produced an encouraging performance on Saturday against the All Blacks, who ultimately ran out 39-21 winners, Wales will have been looking for their fringe players to stake a claim for Test selection.
However, an under-strength side struggled to cope with the Chiefs' pace and power as the Super Rugby outfit raced into a 21-0 lead by half-time.
James Lowe, Toni Pulu and Sam McNicol added further tries after the interval and Charteris, who captained Wales, said it was "unacceptable" to suffer such a heavy defeat.
"We're bitterly disappointed but you've got to give massive credit to the Chiefs," Charteris said. "We let ourselves down. It's frustrating because we knew what was coming, we knew what to expect.
"We've got to have a look at ourselves because it is not acceptable to lose by that sort of margin. They're a very good team but we've let ourselves down."
Injury-hit Wales were forced to leave out Ellis Jenkins due to a sore thigh, although the back-row forward is expected to be fit for the second Test on Saturday.
Gareth Anscombe (hip) and Ross Moriarty (soreness) were also pulled out of the matchday squad.