Humphreys came on as a replacement for Ireland’s Paddy Jackson during the eight-try thrashing of Oyonnax on Saturday, and gets the chance to prove that he is an able replacement.
With seven players away on international duty, director of rugby Les Kiss will know later today who will be released to play for their club.
Humphreys took a very heavy tackle late in the game last Saturday, but has come through any protocols associated with head injuries.
So with the in-form Jackson fairly likely to be involved in the cut for the Six Nations, Humphreys will start at number 10 and with Ruan Pienaar, still suffering from a virus, Paul Marshall will again be at scrum-half.
Ulster will miss lively loose-head Kyle McCall, who got a knee in the head which reopened a cut on the scalp and he will be rested this week.
Worse news for Ulster is that tight-head Wiehahn Herbst will require surgery to repair a knee problem and he will be out for up to eight weeks.
That will see Callum Black and Richard Lutton propping captain Rob Herring.
Ireland flanker Chris Henry will be sidelined for at least another week with his shoulder problem, as Kiss is confident he will be fine for the following week after getting ‘beasted’ by fitness coach Jonny Davis.
Sean Reidy, who had such a good game against Oyonnax will again deputise.
But the good news for Ulster is that full-back Louis Ludik is fit again following a foot injury while young Ireland star Stuart Olding is back in action after a run-out with the Ulster A side last week.
Kiss believes Ulster are facing into a crucial few weeks in the Pro12.
“There is a tough six weeks ahead for all teams in top eight.
“There are few teams with a few games up their sleeves, but that will all even out by the end of February and we now where we are.
“I would say that halfway through this six-week period it will be getting tetchy if you are not putting one or two wins together.
“If you drop one out of three you are still in the hunt but any more losses you will start to drift away.
“There are 30 points up for grabs in that period and it is a chance to position oneself quite nicely for the home stretch.”