With that in mind, the Munster management have called up Academy prop and Ireland Under-20 international Stephen Archer for this week's league trip to Edinburgh.
Munster team manager Shaun Payne said: "Stephen can play either side of the scrum. He had a particularly good game last Friday night against Leinster 'A' in Clonmel, so now he's provided with a great opportunity to put his hand up."
Payne explained that Horan had been feeling unwell in the early stages of the game against Benetton Treviso and after being replaced was taken to hospital where he spent the night as a precautionary measure.
"He's fine now but will see a specialist later in the week, while Tony (Buckley) had a scan yesterday and will not be available for the trip to Edinburgh and given the nature of the injury must remain a doubt for the following game against Ulster.
"Doug Howlett tweaked a hamstring late in the first half but it's not serious enough to omit him for the trip to Scotland at this stage," he added.
Asked about the pressure on Munster's front row resources, Payne said: "Julien Brugnaut is an experienced prop and I thought Darragh (Hurley) did extremely well when he came on against Treviso, and that's always difficult.
"So now both have an opportunity. Of course you don't like to be without your front line players but we have the back up.
"And in the number 2 slot we're fortunate to have the likes of Denis Fogarty and Damian Varley."
Munster coach Tony McGahan will confirm his starting line-up and replacements for the Edinburgh game on Thursday afternoon.
MUNSTER Squad (v Edinburgh) - Backs (11): Felix Jones, Keith Earls, Doug Howlett, Denis Hurley, Ian Dowling, Jean de Villiers, Lifeimi Mafi, Paul Warwick, Ronan O'Gara, Peter Stringer, Tomas O'Leary.
Forwards (15): Nick Williams, David Wallace, Niall Ronan, Denis Leamy, Alan Quinlan, Mick O'Driscoll, Donnacha Ryan, Donncha O'Callaghan, Paul O'Connell, Damien Varley, Denis Fogarty, AN Other, Stephen Archer, Julien Brugnaut, Darragh Hurley.