Sligo man Sheridan played underage rugby with Connacht before making the move to UL Bohemians where he plied his trade under the tutelage of current Munster skills coach Ian Costello. In 2010 he featured for the Ireland Club International squad.
The 25-year-old scrum half moved to the senior set-up at the start of the 2012/13 season after completing two years in the Munster Academy. He made his league debut in February 2013 against Edinburgh at Musgrave Park.
Sheridan went on to make this Heineken Cup debut against Gloucester in October, making his first start at European level in Munster's dramatic 18-17 victory away to Perpignan. He will make his 20th appearance for Munster tonight against Ulster at Ravenhill.
Similarly, versatile prop Ryan is in line to claim his 20th cap for Munster if sprung from the bench for tonight's interprovincial encounter.
The Cork native has represented Munster at Schools, Under-19 and Under-20 levels, and played with the Irish Club International side in 2011 and 2012. He also travelled to Georgia as part of the Emerging Ireland squad for the Tbilisi Cup during the summer.
Ryan made his Munster debut as a replacement away to Cardiff Blues in September 2011 and made four more appearances off the bench that season before moving to London Irish on a loan for the opening games of the 2012/13 campaign.
The 25-yer-old prop started his first game for Munster against Zebre in the final game of last season and has continued his progression this term having featured in seven games already. He made his Heineken Cup debut against Racing Metro 92 at Thomond Park in January 2013.
Fellow prop and Cork native Cronin has exploded on to the scene this season, playing in 14 games and scoring three tries.
A product of the Munster Youths system, Cronin made the move to senior level at the start of the 2013/14 season after completing two years of the Academy programme, during which time he impressed at 'A' level.
He finished last season with two RaboDirect PRO12 appearances, making his senior debut against Leinster at Thomond Park in April.
The 23-year-old made his Heineken Cup debut against Edinburgh at Murrayfield in October, and his first start at European level was away to Perpignan last month.
Munster head coach Rob Penney was particularly pleased with the news of the confirmed signings, stating: "It's great to have these young guys commit their talent and future to Munster.
"It just shows once again the hard work that is being done at grassroots and underage levels for guys of this calibre to break through, and it's great for the province."