Ulster’s director of rugby Les Kiss said Henderson faces a spell on the sidelines though a lot will “depend on how things materialise during the first week”.
Henderson will definitely miss Friday’s PRO12 inter-provincial when Munster take to the road for what will be an emotional trip to Belfast — their first away game since the death of Anthony Foley.
Like all other provinces, Ulster will know today from the Ireland management just how many of their key internationals will be available.
Kiss has added problems with centre Stuart Olding (hip) and lock Kieran Treadwell (ankle) also unlikely to feature.
Tight-head Rodney Ah You is out with a knee problem while both Alan O’Connor and Peter Browne suffered concussion following last week’s Champions Cup win.
However, internationals Darren Cave, Robbie Diack, Luke Marshall, and Dan Tuohy are expected to come through to be available while tight-head Weihahn Herbst played 40 minutes with Ulster A last weekend.
Kiss obviously fears more of the same from Munster after their tumultuous win over Glasgow last week.
“It’s going to be a massive game,” said Kiss.
“The last four games we’ve played there’s been a total difference of seven points between us. So it is going to be a hell of a battle.
“Against the Munsters of this world, you have to be very precise and dogged. You have to be patient as it challenges a lot of components of your mindset. We will be welcoming and it promises to be a great contest. It will be an emotional one in a lot of respects. But it’s a game of rugby and we need to be at our best.
“As an individual you take in that emotion and put it into the right context so that the energy is bundled up in a way you need to perform.”