Jansson missed Leeds' opening two fixtures due to a two-game ban carried over from last season, but could feature as fellow defenders Neil Pennington and Gaetano Berardi are out.
Leeds are still waiting to learn the full extent of the injuries sustained by Pennington (ankle) and Berardi (shoulder) in last week's win at Bolton.
Samu Saiz is pushing for his first start after firing a hat-trick on his debut in the midweek Carabao Cup win against Port Vale, while Cameron Borthwick-Jackson could make his first league appearance for the club.
Josh Harrop could be in the Preston squad for the first time.
The summer signing from Manchester United has had to wait for his debut due to a calf injury sustained in pre-season but is closing in on a return.
Captain Tom Clarke (Achilles) remains out and Alex Neil has a decision to make over who to start up front following Jordan Hugill's midweek brace in the Carabao Cup.
Sean Maguire will be among those hoping to come back into the team, along with the likes of Ben Pearson and Tommy Spurr after Neil shuffled his pack in midweek.