GUINNES PRO12: Ulster's Tommy Bowe to miss crucial Irish derby clash with Leinster

The Irish international had only made his first appearance in the senior squad two weeks again against Zebre in the PRO12 after a serious knee injury playing in the World Cup.

Ulster Rugby said on Tuesday that Bowe had experienced a mild knee reaction after that game in Italy and would be unavailable for selection.

It followed on from the news that number eight Nick Williams would finish his term with Ulster on the sidelines before departing to Cardiff Blues in the summer.

Williams suffered a shoulder injury playing against Glasgow at the end of March and now requires surgery to repair a labral tear.

Louis Ludik (groin) and Wiehahn Herbst (foot) are also ruled out of Saturday’s game in Belfast.

With just two games of the regular league season left and Ulster still fighting for a place both in the European Champions Cup for next season plus the league’s play-offs, Saturday’s game is seen as a must win affair against their arch rivals.

Leinster are top of the table with Ulster in fourth place two points ahead of Scarlets.

A win would keep Ulster’s chances of making the play-offs alive and director of rugby, Les Kiss, knows the side face a stiff examination of their title credentials.

“If you look at the way the PRO12 stands at the minute with six teams still in the hunt, I have got to say it is the toughest PRO12 there has ever been.

“All the other pressures having to qulaify and all that sort of stuff and then ultimately to come up against Leinster this weekend puts another magnifying glass around the pressure.

“We just know it is going to be a big one for us and if we can get over the line it is an important one for us.”

Kiss has one mission and that is get the victory.

“There was an expectation on us to deliver five points in Zebre and we achieved that.

“The expectation is for us to deliver the win this weekend and if we do that it is a case of missions accomplished,” he added.