Schaub hurt the Lisfranc joint in his right foot in the second quarter of Sunday's 37-9 win in Tampa Bay. He stayed in the game, but only threw three passes in the second half.
Coach Gary Kubiak called the injury "significant" and Schaub said on his weekly radio appearance with KILT-AM on Tuesday that his foot "is not visibly looking too good." Schaub said he will meet with more doctors over the next week.
"When you look at it, it's pretty colorful and everything," Schaub said. "It's pretty sore and beat up right now. But we're going to search out some other opinions and just do as much as we can to get it right here in the near future to see what can happen."
Schaub said the injury occurred when his foot got caught underneath new Tampa Bay defensive tackle Albert Haynesworth on a quarterback sneak when the Texans were backed up near their own goal line.
"I didn't really know how bad it was," Schaub said.
Kubiak said the Texans will determine by next week if Schaub would return this year. If doctors tell him that surgery is necessary, Schaub said he'll "probably" be out for the rest of the season. But he's hoping to find other courses of treatment that would speed his recovery.
"I'm not one to give in to something like this that easily," Schaub said. "It doesn't look good. My foot is pretty much the size of a cinder block right now."
One certainty, Schaub said, is that doctors have told him he can play again.
"It's not career-ending," Schaub said. "No way."
The AFC South-leadingTexans (7-3) have a bye week before their final six regular-season games. Matt Leinart will step into Schaub's role and make his first start since 2009 in Houston's next game, at Jacksonville on Nov. 27.
Leinart was cut by Arizona and signed by Houston in September 2010. He didn't take a snap last season, but felt comfortable enough with Kubiak and the offense to return.
"This isn't his first rodeo," Schaub said of his replacement. "He's played some football in this league. He knows how to play the quarterback position.
"Our time spent together here over the last year and a half, two years, he's definitely prepared."
The Texans acquired Schaub in a trade with Atlanta in March 2007, and he's started every game since the start of the 2009 season. Adding to Schaub's frustration now is that Houston has won four in a row and continues the best start in franchise history.
"It's been really impressive to see the group really rally around one another," he said. "Over the course of the last five years, this organization has gone from what it was to what it is now, and a team that's atop the AFC.
"It's just been impressive," Schaub said, "and I'm extremely proud of the guys in the locker room, and what they've been able to do. We just need to keep that going here."