The Scot led the British women to a breathless, last-gasp 10-8 win over Korea yesterday morning to record her third successive win, but in the evening session she suffered her third loss, going down 8-6 to Switzerland.
That means the British women now share third place with China and Switzerland and must win one of their two remaining games, against Russia and Denmark tomorrow to ensure at least a tie-break.
But Muirhead was in no mood to lick any wounds and insisted she was ready to rouse her team for the challenge of throwing their own stone of destiny.
"It's in our own hands," Muirhead said. "We have a day off today and we will definitely take advantage of that, and then tomorrow we need to come back strong against Russia and Denmark.
"We won't do an awful lot today. We do have some practice time, but we won't look at anything in particular, nothing technical.We're all throwing the stones great. I think I just had the brush in the wrong place a lot of the time, but that's what happens.
"We'll have a bit of rest time, a bit of time together and maybe catch up with our families and things.
"We are not down and out. We have a long way to go, it is in our own hands, so we'll be really pushing hard on Monday."
There was drama in the morning match against Korea when Muirhead's team were 8-7 down going into the final end. But with the last stone of the game, Muirhead came round a guard to tap out a counting Korean stone and score three points for a 10-8 victory.
In the evening game against Switzerland, the British team were slow out of the blocks and were in real trouble after the sixth end when Muirhead missed a double take-out to leave Switzerland's Mirjam Ott an easy draw for three and a 6-2 lead. Muirhead's team fought back but it was too little and they lost 8- 6.
Muirhead was critical of the ice, which she claimed might have been affected by debris from the overhead television camera.
She said: "It's not often I say we were unlucky or struggling with ice, but I did struggle with it, I think all of us did. I'm not using that as an excuse. We just weren't sharp enough, but if we can play like we did in the morning and the way we did in the second part of that game, we will keep the ball rolling."
In the afternoon session, the men lost to Canada 7-5 when skip David Murdoch's last stone of the game just missed. However, even with that result, they remain on track for semi-final qualification.
"You're talking one millimetre," said Murdoch. "One millimetre on the high side and that's the game. That was a pretty cruel blow. We were tactically smart, we played well. We put a lot of pressure on them, but we didn't get the win."
The men share third place and play Norway today and table-toppers China tomorrow and the way the standings lie, they are already assured of a tie-breaker. However, they will be looking to book a direct semi-final slot from their two remaining games.
Women's standings (played, won, lost): 1 Canada 7, 7-0; 2 Sweden 7, 5-2; 3=China 7, 4-3; 3=Great Britain 7, 4-3; 3=Switzerland 7, 4-3; 6 Russian Fed 7, 3-4; 7=Japan 6, 2-4; 7=Korea 6, 2-4; 9 Denmark 7, 2-5; 10 United States 7, 1-6.
Men's standings: 1=China 7, 6-1; 1=Sweden 7, 6-1; 3=Canada 7, 5-2; 3=Great Britain 7, 5-2; 5 Norway 6, 3-3; 6 United States 6, 2-4; 7=Denmark 7, 2-5; 7=Russian Fed 7, 2-5; 7=Switzerland 7, 2-5; 10 Germany 7, 1-6.