The January signing could be included in defence after Mowbray criticised individual mistakes made by his back-line which led to Boro throwing away a 3-1 lead at home to Swansea to lose 4-3 last time out.
However, due to Haas` lack of experience of English football, the injury-hit defence could stay the same.
Mowbray`s injury woes at the back are easing as left-back Andrew Taylor (hamstring) has a chance of being available, as does Julio Arca (toe). Right-back Justin Hoyte (hamstring) is closing on a return and centre-back Stephen McManus (ankle ligaments) is making good progress, although he is still three or four weeks away from full fitness.
New signing Merouane Zemmama is pushing for a starting place after making his debut as a substitute against the Swans, on-loan Hamburg midfielder Mickael Tavares could be involved after recovering from a fractured toe as could forward Tarmo Kink who has missed a few weeks with a virus.
Midfield trio Willo Flood (knee), Rhys Williams (hip) and Kevin Thomson (hairline fibula fracture) have stepped up their recoveries from injury. Flood and Williams played 45 minutes of a reserve-team match against Sheffield United and Thomson has resumed light training.
Source: PA
Source: PA