A must-win for both sides in the fight for Champions Cup rugby, Connacht and Cardiff clash at the Galway Sportsground this evening (5pm).

Connacht’s Pat Lam, who says there will be no excuses if his side fail to take full points from this Pro 12 fixture, has made only three changes to the starting line-up from the team that bagged two points from their loss to Glasgow.

Scrumhalf Kieran Marmion is the only change in the back line, fit-again No 8 Eoin McKeon makes a timely return for the injured Eoghan Masterson, and prop Finlay Bealham comes in for fellow tighthead Rodney Ah You, who is sidelined with a hamstring strain.

And with Nathan White on World Cup duty, Lam has dipped into his Academy to name Sligo and Ireland U-20 prop Conan O'Donnell on the bench. It's three seasons since Connacht recorded a victory over the Blues (they let two chances slip last year – a draw at home and a controversial one-point defeat in the Welsh capital) but Lam says "it's a new season".

“Whether it’s Cardiff or Leinster, we know these games are going to count at the end. Having our home support will certainly help us.”

Similar to Connacht, Cardiff suffered a close second-round defeat to Leinster after a bright opening victory over Zebre, and coach DannyWilson has also made three changes, bringing in left wing Richard Smith, lock Lou Reed who partners Kiwi Jarrad Hoeata, and Ellis Jenkins in the back row.