Leeds club captain Richard Naylor could make a surprise return to the squad for the home clash with Scunthorpe.
Naylor, 33, has been sidelined since late November after undergoing a minor knee operation, but completed 45 minutes in a midweek reserve-team fixture at Scunthorpe and could come into contention at Elland Road.
Recent permanent signing Andy O'Brien is expected to start at the heart of defence alongside Alex Bruce, who turned in one of his best displays in last week's FA Cup clash at Arsenal.
Neill Collins is also vying for one of the two central defensive berths, while long-term absentee Patrick Kisnorbo returned to light training at Thorp Arch this week following a ruptured Achilles tendon.
Grayson must decide whether to retain fit-again Ben Parker at left-back or recall Andrew Hughes, while Neil Kilkenny is still away with Australia in the Asian Cup.
Iron boss Ian Baraclough has a number of injury worries ahead of his side's trip to Yorkshire.
Midfielder Michael O'Connor injured his knee in training on Thursday morning and was on crutches afterwards, while Cliff Byrne and Rob Jones remain doubtful with back injuries.
Defender David Mirfin and winger Garry Thompson are also struggling with knee and groin injuries respectively.
Baraclough said of O'Connor's injury: "It was a training ground accident on Thursday morning and that just shows that when it's not going for you it's not going for you.
"Hopefully it's not too serious and he'll be in the reckoning for Saturday.
"The crutches were just there so he doesn't put any weight on the knee. He's still in contention."
