Ulster and Connacht both hope to name their sides this afternoon as they return to European action on Friday night.
Mark McCall is expected to welcome back captain Andy Ward to the starting line-up, while David Humphreys is fit again after playing 80 minutes against Connacht on New Year's Day. Simon Best is the major injury doubt.
In recent weeks every game has taken on monumental importance for Ulster and defeat against Gloucester at Ravenhill would kill off their already slim hopes of making the quarter-finals for the first time since 1999.
McCall will also be keen to eradicate the memories of the 55-13 hiding Ulster suffered at Kingsholm in October with a typical Belfast welcome for the English visitors.
"It's great that there are so many big games," said McCall. "In some ways the Connacht game was massive. We think we have improved since we last played Gloucester but we'll only get an indication of where we are after Friday night."
Connacht travel to Grenoble to face the Dean Richards-coached side who are struggling in the relegation zone of the French league. However, Grenoble have the pedigree having beaten Leeds Tykes and Beziers to reach the quarter-finals of the Challenge Cup.
Munster will release a 26-man squad today for their encounter with Neath-Swansea Ospreys at Thomond Park on Saturday.
Leinster will select their team tomorrow for Saturday's match away to Bath with the only serious injury concern surrounding Malcolm O'Kelly.
Bath have virtually a full team of players on the treatment table and have problems at hooker ahead of Saturday's pool match, with both Jonathan Humphreys and Lee Mears injured. Head coach John Connolly last night said the professional game in England needed to take urgent action to protect its players after another weekend produced a serious injury, with the Leicester number eight Martin Corry ruled out of the Six Nations opener against Wales because of a dislocated elbow.
"Injuries have always been part of the game, but the sport has become a lot tougher in the last eight years and professional rugby is becoming a victim of its own success," said Connolly. "Players are in better condition than ever before, fitter and bigger. The increase in the number of injuries is the inevitable consequence but it is the nature of them which is the real cause for concern.
"There are issues which have to be looked at, such as padding and protection, but it is imperative that players have a guaranteed break in the off-season."
