Pat joined Glasgow on a full-time contract in May 2009 and signed a new two-year deal in 2011.
Pat received his rugby education at Millbrae with Ayr RFC and also with the West of Scotland club came through the national age-grade ranks before signing a professional contract with the Warriors.
He played U18, U19 and U20 for Scotland and has established himself as one of the most consistent hookers in the country.