Former Bournemouth defender Jack Simpson is set to replace him alongside Connor Goldson in Sunday's Old Firm clash.
The Swedish centre-back limped off during last weekend's shock Scottish Cup defeat to St Johnstone and has now been ruled out of Gers' final three games - along with midfielder Scott Arfield - though should make the European Championships.
Gerrard said: "We won't have Fil Helander, probably for the remainder of the season. The same goes for Scott Arfield, so we're a little bit light at centre-back and in midfield.
"Scott's injury is in the ankle area and Fil's is in the knee area. In terms of what the doctor's diagnosis on them is I'm still waiting for certain information and scan results.
"But I think Fil has got a good chance (of making the Euros)."
Rangers and Scotland midfielder Ryan Jack has already been ruled out of this summer’s tournament.