The Warriors, who were relegated from the Aviva Premiership this season, have recruited the duo in preparation for next season.
Speaking after the deal was announced, O'Shea told the club's website: "I would like to thank all the coaches and players at Munster for their support and encouragement in helping me develop as a player to date.
"However I am very keen to develop further and believe that playing regularly with Worcester is the right platform for me to bring on my game over the next few years.
"I am excited to be joining Warriors as they are a club which have placed a big emphasis on developing young players to build a successful team."
Bruzulier was part of the Saracens squad which finished as runners-up in the 2011 Aviva Premiership Seven Series, before moving to the French Pro12 league.