The 36-year-old has played 114 times for Warriors in his two spells at the club and has scored 30 tries for the PRO12 side.
Sean started his career with English side Rotherham in 2000 before joining Glasgow. He also had spells with Northampton and Scarlets before returning to the Warriors in 2012.
Gregor Townsend remembers Sean coming through with his bother Rory and the buzz they were creating around Scottish rugby.
Speaking to glasgowwarriors.org, Gregor said: "I was coming to the end of my playing career when Sean and Rory were coming through and there was a real buzz around them.
"They were two exciting players who had come into the Glasgow set-up around the same time and went on to have outstanding professional careers.
"I took a real interest in Sean's game when he was playing at Northampton and started to become a regular in the Scotland team."
Sean is the third most capped Scotland player, winning 105 caps between 2004 and 2016 and Gregor believes his double against France in 2006 was a defining moment.
He said: "Probably as a supporter seeing Sean score two tries against France was a real breakthrough moment, it was a brilliant win for Scotland that day and Sean - with his gloves and blonde hair - was a key part in the victory.
"He'll be one of a very small number of players to have played in every position in the back five. Obviously he played most of his rugby on the wing, but he also performed very well at inside centre when I was an assistant coach with the national team back in 2011.
"He was a success for club and country at outside centre and in one game against Wales I remember he came on at full-back and had very good game at BT Murrayfield.
"Sean has shown a real consistency and resilience to get over a couple of major injuries and to continue to play at a really high level."
The Perth-born winger scored the bonus-point try against Connacht in the Warriors last game at Scotstoun and Gregor hopes that wasn't his last in a Glasgow shirt.
He added: "It was really good to see Sean score that try against Connacht a few weeks ago. You could tell from the players' reaction how much Sean means to them and our supporters loved it.
"It was the bonus-point try and a really good finish. It would be great to see Sean run in one or two more tries before he finally hangs up his boots."