Schaub, who has a $14.5 million salary-cap figure and a $10 million base salary for 2014, became expendable when the Texans signed former Tennessee Titans quarterback Ryan Fitzpatrick to a two-year deal Thursday night.
Not long after Houston acquired Fitzpatrick, Oakland made its final move on Schaub.
The Cleveland Browns had expressed some interest in Schaub, who could have been reunited with former offensive coordinator Kyle Shanahan. But the Raiders want Schaub even more, according to a source.
The expected trade between Oakland and Houston, two teams scheduled to pick in the top five, could impact the 2014 draft and how high quarterbacks will be selected.
Oakland would have Schaub, the veteran quarterback atop its offseason wish list and someone who reduces the Raiders' pressure to use their first-round pick -- No. 5 overall -- on a signal caller.
Houston, which owns the No. 1 overall pick, would have an even greater need at the quarterback position by trading Schaub.
The Raiders currently have three quarterbacks on their roster in Terrelle Pryor, Matt McGloin and Trent Edwards. Coach Dennis Allen said he was not sure whether the team's quarterback of the future is in the locker room at this time.
ESPN.com Raiders reporter Paul Gutierrez contributed to this report.