Boykin injured his right ankle last week during the Horned Frogs' 23-17 victory over Kansas and had been listed as questionable all week.
Redshirt freshman Foster Sawyer started in Boykin's place and enjoyed a strong first quarter, completing seven of his first eight passes for 103 yards and a touchdown that put the Horned Frogs up 7-0. He was just 1-of-10 after that with three interceptions and was eventually replaced midway through the third quarter by Bram Kohlhausen.
With TCU missing Boykin and wide receiver Josh Doctson, the Horned Frogs (9-2, 6-2, No. 18 CFP, No. 11 AP) turned the ball over four times, leading to 24 Oklahoma points. After trailing 30-13 in the fourth quarter, TCU had a chance to tie the game after Kohlhausen's 14-yard touchdown pass to Emanuel Porter with 51 seconds remaining. Instead, the Horned Frogs went for the win by attempting the 2-point conversion but were turned away by Oklahoma's Steven Parker, who batted away the late comeback attempt.
Sawyer replaced Boykin in TCU's win over Kansas. He completed just 1 of 7 passes, though his lone completion was a 42-yard touchdown to Shaun Nixon.
Earlier this week, Patterson said Doctson would miss the rest of the regular season with a wrist injury.
Boykin and Doctson both were named among the 15 semifinalists for the Walter Camp Player of the Year Award.
The Associated Press contributed to this report.