Petke even said RSL now has a mental performance specialist working with its players.
"We need to amp it back up," he said. "That's what we have to do."
RSL's coach said Designated Player Joao Plata trained off to the side Tuesday because the 25-year-old forward missing his flight back to Salt Lake City. Plata has started in the last two losses, but he has yet to register a goal in his injury-plagued start to the year. The dynamic goal-scorer signed a multi-year extension with RSL in late February.
"I won't accept that. The players know that," Petke said.