Koren was rested on Monday night in the win at Burnley, with Alex Bruce employed as a holding midfielder, but the Tigers manager may want to revert back to a more attacking formation at the KC Stadium.
Bruce is expected to be without midfielder Corry Evans again as he sustained a thigh strain in the warm-up ahead of last week's defeat at Crystal Palace.
Defender Abdoulaye Faye (calf) has shaken off his recent injury and is pushing for a recall, as is striker Jay Simpson.
Sone Aluko and Matty Fryatt remain sidelined with Achilles tendon injuries.
Hull trail leaders Cardiff by four points in second place having won five of their last seven league games.
Dexter Blackstock is likely to be missing for Forest.
Blackstock was forced off after 34 minutes of last Saturday's 3-1 home win over Wolves with a hamstring injury and he is a big doubt ahead of the game at the KC Stadium.
Fellow strikers Billy Sharp (chest infection) and Darius Henderson (knee) were also struggling last weekend and boss Billy Davies will hope that they have improved over the course of this week.
On-loan Norwich centre-half Daniel Ayala (hamstring) and fellow defender Dan Harding (calf) are both close to a return to the squad.
Davies remains unbeaten since returning as manager last month, stringing together five straight wins after drawing his first game in charge.
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