Connor McDavid and Leon Draisaitl combined for 11 points in their last affair with the Avs but all the production for the Orange & Blue was courtesy of Jujhar Khaira and Darnell Nurse on Wednesday.
Khaira returned to game action after missing a pair of outings, putting the Oilers ahead in the first with a power move to the net.
The forward worked his way behind the goal-line then curled above the crease, backhanding home his fifth of the year. Nurse, picking up his 10th assist, received the lone helper.
McDavid's 11-game production streak, where he had 12 goals and 12 assists, halted in the defeat.
"It's not the way we wanted to finish this trip," Gaƫtan Haas, alluding to the team's five-game road swing which ended at 3-2-0, said.
The Oilers didn't want to use the depleted lineup as an excuse in the loss and agreed with Tippett's post-game assessment.
"We could have played smarter but we didn't," said Khaira. "There's no excuse. We know that in the dressing room."
There was no update on Chiasson post-game. He left the match after the hit from Graves and did not return.
"It was a tough game," said Koskinen, who is 9-2-2 this year. "They were coming hard and we were short of guys."
The Oilers return to Edmonton for a match with the Vancouver Canucks on Saturday.
"We need to be better next game," said Koskinen.