The 32-year-old Sunderland defender will run out at Tottenham tomorrow knowing the Black Cats will be playing their football in the Barclays Premier League once again next season no matter what the result at White Hart Lane, something which was in doubt right up until Wigan's defeat at Arsenal on Tuesday evening.
He will do so have played a key role for club and country during a campaign which has seen him captain both Sunderland and the Republic of Ireland and help steer them through decidedly choppy waters.
Martin O'Neill was shown the exit door at the Stadium of Light in March and Giovanni Trapattoni's reign came under serious threat after a 6-1 home World Cup qualifier defeat by Germany in October but, through all the turmoil, O'Shea stood tall and continued to do what he has done with such distinction throughout his career.
He said: "Thankfully the fitness has been very good this year, that's been the main thing.
"You are maintaining everything off the pitch in terms of the work you do in the gym and the core work - especially when you are getting into your 30s rather than your 20s, it's definitely needed more.
"But also you know you are preparing yourself right and you can cope with it.
"Thankfully, I have never had the major injuries that can hold you back towards the latter end of your career. I feel very fresh."
O'Shea will make his 44th appearance of the campaign at Spurs, but while many of his team-mates will then be heading off on the summer holidays - or at least after manager Paolo Di Canio has dismissed them - he will still have work to do.
Ireland have four fixtures before their season draws to a close, starting with the much-anticipated friendly against England at Wembley on May 29 and a re-match of their Euro 2012 finals clash with eventual champions Spain at Yankee Stadium in New York on June 11.
But it is the qualifier against the Faroe Islands, which is preceded by another friendly clash, this time with Georgia, at the Aviva Stadium in Dublin on June 7 which represents the main business for O'Shea.
It will be a grueling end to the season for the former Manchester United man if he is involved in all four fixtures but, as ever, he is ready for the challenge.
He said: "Most importantly, we have the qualification game against the Faroes, but also there's the small matter of a friendly against England as well, and then there's Spain in New York after the qualifier, which is an interesting one.
"But we will wait and see. We'll take one at a time."
In the meantime, the Black Cats will attempt to finish their season on a high after limping over the finishing line without kicking a ball.
Di Canio had hoped they would seal their top flight status by beating either Stoke or Southampton in consecutive home games, but both ended 1-1, meaning victory for Wigan at the Emirates Stadium would have set up a tense final day.
But while the pressure of the relegation fight may have gone, there will be no let-up from the manager.
The 44-year-old Italian said: "We still have one game to go and we have to make sure that we are going to perform well because I don't want to finish fourth from the bottom if it's possible.
"With even a draw, potentially we can be sixth from the bottom. But we have to make sure that we are going to put everything into this game and not finish fourth from the bottom."