The 23-year-old was clearly disappointed but hopes his performances in the GUINNESS PRO12 will ensure he adds to his four Ireland caps.
Marmion told the Galway Advertiser: "The lads ahead of me are good players, experienced and have been around the game for a long time, and I am still learning from those guys.
"It was good to be around them and I am trying to close the gap, taking on board what they have and trying to bring it to my game.
"I want to be there as soon as possible, I don't want to leave it a few years. I want to kick on now and hopefully this season put my name forward and nail down the spot."
Marmion suffered a minor set-back on the opening weekend of the GUINNESS PRO12 season as he picked up a hip injury in the victory over Newport Gwent Dragons.
But after a break during the gap in GUINNESS PRO12 fixtures, Marmion is raring to go when Connacht welcome Cardiff Blues to the Sportsground next weekend.
He said: "This is a huge game for us. Cardiff was one of a few games last season that was there to win and we only had ourselves to blame.
"They are always difficult, so to get four or five points from them next week would be huge in terms of the league and our season."
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