Ulster say they are taking "every possible step" to ensure Saturday's Heineken Champions Cup meeting with La Rochelle goes ahead as planned at Kingspan Stadium.
The recent cold snap has seen their Ravenhill pitch frozen, and with temperatures expected to stay close to freezing in the coming days, there are concerns about whether or not it will thaw out in time for the Saturday kick-off (5.30pm).
The province say a protective cover has been placed on the surface, while ground staff are bringing in heaters to help protect the surface.
"Ulster Rugby is continuing to take every possible step to preserve the playing surface ahead of this weekend's Heineken Champions Cup fixture against reigning champions Stade Rochelais, scheduled to take place at Kingspan Stadium on Saturday 17 December," an Ulster statement reads.
"Frost covers have been on the pitch all week and additional measures such as heaters are being brought in. Efforts will continue, with sustained freezing temperatures forecast over the coming days.
"The club is in regular contact with tournament organisers EPCR, and we will provide daily updates for supporters via our social media channels."
The Irish Independent have reported that the RDS is on standby to host the game if Ulster can't guarantee the pitch will be playable.
