Sebastian Vettel says he just didn't have the pace to fight at the front of the pack in Spa after suffering only his second Q2 exit of the season.
The reigning World Champ looked out of sorts in final practice on Saturday morning, although that was surmised to be because Red Bull were concentrating on race-pace instead of qualifying form.
However, it was more of the same in qualifying at the Spa circuit as the German failed to make it into the pole position shoot-out for only the second time this season.
"I was pretty happy with my lap, it was just not quick enough unfortunately," Vettel told Autosport.
"I missed the last part of qualifying by such a little amount and that's a shame, but that's racing.
"It's frustrating but it could be the other way around and you are in and somebody else is out.
"But obviously there are no points today and the race is tomorrow."
He added: "I was quite surprised that this morning it felt pretty alright and this afternoon it just didn't come together.
"The lap was clean, there were no mistakes, but it wasn't quick enough."
Vettel was 11th fastest but will start Sunday's race P10 after his team-mate Mark Webber was hit with a gearbox penalty.
And like Vettel, Webber was also left to lament Red Bull's lack of pace as he was only seventh fastest in qualifying.
"I think we'd have liked to have been further up the grid, we weren't fast enough to challenge for the front row," he said.
"I'd have liked to have been further up to take the sting out of the penalty.
"In general I think I got enough out of what we have, which at the moment is not enough."