Oakland coach Dennis Allen evaded the question when asked if McGloin would remain the starter when Pryor has recovered from a knee injury.
"Listen, here's what I'm going to do - I'm going to enjoy this win, all right," Allen said. "We're going to go back and we'll evaluate. But he definitely did a very good job today."
McGloin was 18 of 32 for 197 yards. Houston's Case Keenum, also an undrafted free agent, was benched after Houston's offense stalled in the third quarter.
McGloin threw touchdown passes of 5, 16 and 26 yards to help the Raiders score their most points of the season.
"There is always more to prove and more to do," McGloin said. "I think I got off to a good start, but we will see."
Kubiak wasn't on the sidelines, instead coaching upstairs from the booth on doctor's orders two weeks after collapsing at halftime of Houston's game against Indianapolis.
Johnson and Schaub were yelling at each other on the field after the play and the screaming match continued on the sidelines, a clear indication of the frustration on a disappointing team that was supposed to contend for a Super Bowl.
Johnson said the argument came because he "messed up" and didn't finish the play.
"We just exchanged some words," he said. "It's just heat of the moment. Once we came in the locker room, we talked about it, left it alone so I'm not worried about that. Me and Matt have played a lot of football together."
Schaub also brushed off their disagreement.
"It's just emotions, emotions of the game, a culmination of a lot of things, but stuff we'll keep between us," Schaub said.
Kubiak replaced Keenum with Schaub after Houston's first three drives of the second half all ended in punts. Schaub was terrible early this season and hadn't played since Oct. 13, after he was benched following an injury.
Keenum threw for 170 yards with a touchdown and an interception. Schaub had 155 yards passing.
Kubiak wouldn't say who would start next week.
Houston punted on Schaub's first drive before settling for a 26-yard field goal on the second when the offense stalled after getting a first down at the 10.
A 30-yard field goal cut the lead to 28-23 with about eight minutes remaining.
Houston tied it at 14 when Keshawn Martin let a punt bounce off the grass and his chest before scooping it up and dashing 87 yards for a touchdown about three minutes before halftime. It was the longest punt return for a score in franchise history.
Randy Bullock made his first field goal of 50 or more yards with a 51-yarder to give Houston a 17-14 lead just before halftime.
McGloin's first career touchdown came when he hit Denarius Moore on a 5-yard slant to put Oakland up 7-0.
Houston's second miscue came when Keenum threw his first career interception as he was being hit by Stacy McGee. It broke a streak of 105 pass attempts without an interception for Keenum.
NOTES: Former Presidents George H. Bush and George H.W. Bush were on the field before the game and the younger Bush did the coin flip. ... McGloin is the 17th quarterback to start for the Raiders since the start of the 2003 season. ... Oakland defensive tackle Daniel Muir and right guard Mike Brisiel both sustained knee injuries and Allen said he'll know more after they have MRIs.
Copyright 2013 by The Associated Press