Gibbins was found guilty at a disciplinary hearing in London today (Wednesday) after he was cited for striking Exeter Chiefs forward Jacques Vermeulen "with his shoulder in a dangerous manner".
He was yellow carded at the time, but at today's hearing, a committee consisting of Philippe Cavalieros (France), Chair; Donal Courtney (Ireland) and Antony Wheat (England), considered videos of the incident and heard submissions from Gibbins, who accepted that he had committed an act of foul play, but didn't feel the offence warranted a red card.
A statement from tournament organisers read: "Submissions and evidence were also heard from the Glasgow Warriors Head Coach, Dave Rennie, from the Glasgow Warriors Team Manager, Kenny Brown, and from the EPCR Disciplinary Officer, Liam McTiernan.
"The Committee upheld the citing complaint, finding that Gibbins had made contact with Vermeulen's head in a dangerous manner that had warranted a red card. It then determined that the offence was at the mid-range of World Rugby's sanctions and selected four weeks as the appropriate entry point.
"Taking into account the player's clear disciplinary record and timely expression of remorse, the Committee reduced the sanction by the maximum of 50% before imposing a two-week suspension.
"As a one-week suspension ordinarily results in a player missing one match, and as Glasgow Warriors' next fixtures are scheduled for Saturday (18 January) and 14 February, Gibbins is free to play on Monday, 17 February."