Head coach Pat Lam said yesterday that Faloon's foot injury was 'a definite long-termer' and the province have now said that the 27-year-old will require surgery and is expected to be out of action for up to five months.
Asked about the province's openside options, Lam added: "We have Jake (Heenan) who is a seven first and foremost, Aaron Conneely, Rory Moloney, who is straight out of school.
"It doesn't help that Eoin McKeon is still out injured, so we have two experienced guys who had expected to feature a lot for us now unavailable."
Meanwhile, David McSharry and Denis Buckley have stepped up their rehabilitation programmes in recent days and have rejoined training, but remain unavailable for selection just yet.
Craig Clarke, who made his debut for Connacht last time out, trained this week and is in the frame for selection at home to the Ospreys this Saturday evening (kick-off 5pm).
Robbie Henshaw was involved in the two-day Ireland training camp in Kildare in the early part of this week and will return to Connacht training tomorrow ahead of the Ospreys match.
The round 4 fixture will not be televised so the only way to see all the action is to get down to the Sportsground. Tickets for Connacht v Ospreys are available from tickets.ie, the Connacht Rugby office and from Centra and SuperValu stores province-wide.