Striker Alexander, who climbed off the bench to hit the winner against Leeds last weekend, is a major doubt with a heel injury and midfielder Schofield is rated 50-50 after picking up a calf niggle.
If Schofield is fit boss Kenny Jackett is likely to name the same starting line-up for the third game running.
Andy Frampton serves the final game of his three-match ban, although he will be unavailable for another month after suffering an ankle injury making the challenge that earned him the red card.
Fellow defenders Darren Ward (knee), Zak Whitbread (hip), Pat O'Connor (cruciate) and Danny Senda (Achilles) remain on the sidelines along with midfielder Ali Fuseini (knee).
