After emerging as a player of immense promise, O'Shea established himself as a squad player of real importance at Manchester United, though he never quite reached the dizzy heights of his first season as a first-teamer.
Able to play anywhere in defence as well as in a midfield holding role, he's a versatile customer who even starred as sub goalie as United punished Spurs 4-0 in February 2007. O'Shea's United bow came in a 3-0 League Cup defeat at the hands of Aston Villa in October 1999 and the Irishman was then loaned out to Second Division side AFC Bournemouth in January 2000, scoring his first goal in a 3-1 defeat at Millwall. He then moved to Belgian club Royal Antwerp on loan and made his full Republic of Ireland debut in August 2001 against Croatia, scoring an own goal in a 2-2 draw.
O'Shea really made his mark in United's 2002-03 title-winning campaign, undoubtedly the best of his career. Possessing the great clichÃ© of "a good touch for a big man" and a willingness to attack from full-back, he impressed to such an extent that he was shortlisted for the PFA Young Player of the Year award, losing out to Jermaine Jenas. O'Shea's 2003-04 campaign was not as noteworthy, and though he began to rediscover his form in 2004-05, the left-back slot belonged firmly to Gabriel Heinze, before he was himself usurped by Patrice Evra.
O'Shea has found himself called upon to fill a number of positions in the intervening years, and has always done so with the minimum of fuss. He has scored some crucial goals for United, including a memorable winner in a 1-0 victory over Liverpool at Anfield in 2007 and a Champions League semi-final winner against Arsenal in 2009. The 2008-09 season was O'Shea's most impressive in recent times as he played 42 games in all competitions, including all of United's Champions League games as they lost out in the final to Barcelona.
After helping United to their 19th league title, though, he decided to leave in pursuit of a new challenge at Sunderland, arriving just hours after Wes Brown.
Strengths: The Irishman's undoubted strength is his versatility, while his unflustered style of defending made him a key part of the United squad for many years.
Weaknesses: O'Shea is not blessed with speed and can get caught out against genuine pace.
Career high: Scoring a last-minute winner against Liverpool at Anfield in 2007 to silence the Kop and keep United on course for their first league title in four years.
Career low: Failing to build on his initial promise, his ability was reportedly criticised by Roy Keane in his infamous MUTV tirade in 2005.
Style: Reliable and calm, a player who enables others to flourish in the attacking third.
Quotes: "He is a great professional. The boy never complains. He is happy to play anywhere. He has not always been a number one choice but he produces 30 performances a season and it is a contribution we are grateful for. He is so versatile and offers such great value for us" - high praise from Sir Alex Ferguson after O'Shea's Champions League semi-final winner against Arsenal.
Trivia: Of the nine Premier League goals he scored for Manchester United, five came in the 80th minute or later.