Griffin has come through the Connacht Academy system under the guidance of Academy Manager Nigel Carolan. He earned his first Academy contract in 2009 and quickly came to the attention of the senior coaches with his blistering acceleration and neat footwork.
He won nine caps for the Ireland Under-20s, scoring tries against Argentina and Samoa in the IRB Junior World Championship last year as well as tries against Wales and England in the 2010 Under-20 RBS 6 Nations.
The Barna youngster earned the man-of-the-match award for his part in Connacht's 26- 22 victory over Samoa last November.
Meanwhile, McSharry joined Connacht this season having been part of the Leinster Academy. The 21-year-old former Templeogue College pupil has played for Ireland at Under-18 level and was a member of Ireland's Under-20 World Championship squad this past summer.
At 1.88m and 94kg, McSharry has already proven his credentials playing for UCD in last season's Ulster Bank League and is quickly becoming known as a key component in the Connacht defensive line.
His attacking prowess came to the fore last weekend when he earned the RaboDirect PRO12 man-of-the-match as well as scoring his first try in Connacht's narrow defeat to Benetton Treviso.
The Dubliner has been an ever-present fixture in the Connacht team since making his debut back last month, earning his second cap for the province in Connacht's maiden Heineken Cup match against Harlequins at the Twickenham Stoop.
Looking forward to more big games with the westerners, McSharry said: "The best way to develop for us young lads is playing games and that's what we are getting to do here, I'm delighted.
"I had no hesitation when the contract was put in front of me. I have played in a few huge games now and those games can do wonders for you.
"Playing in those big games is worth 10 training sessions. This is what I want to be doing, playing as much as possible."
Griffin, who is also 21, added: "Well I'm from here so I'm delighted to be playing for Connacht and with Dave for another two years.
"Hopefully that will go well, we have played together (Ireland Under-20s) so I'm really happy, happy out to be here for two years."