Muirhead's rink sealed their sixth win of this week's preliminary stage, beating Latvia 10-4 to set up a grandstand evening clash with Russia.
Russia are top of the table and Scotland second, so Muirhead is expecting a tough challenge.
"It's going to be a hard game. It's important for rankings so we're going to go out there and play the way we have been playing," Muirhead said.
In the third end of Wednesday morning's rubber, Latvia skip Iveta Stasa-Sarsune had the chance to score two, but was heavy on her draw.
Scotland in the next end scored three points and then four more in the sixth end, Latvia conceding after the seventh.
Russia had a fast start against Norway in their penultimate pool game and stole two both in the second, third and finally in the sixth end, with Norway conceding after that.
"Norway made some mistakes and we just played our game and got lucky," said Russia's Anna Hasselborg.
Hosts Sweden also qualified for the knockout stages, beating Czech Republic 8-4 and Switzerland secured safe passage with a 11-6 victory over Estonia.