Speaking at a press conference following the announcement, Harrington expressed his delight at the news.
"Because you are putting it on the line when you become a Ryder Cup captain", Harrington said.
"Obviously I'm thrilled", said the three-time major victor. "I'm thrilled but it's not something I take on without a certain amount of trepidation". "I'm really conscious that I have to find that edge and add to it".
Referring to Europe's thumping 17.5-10.5 win over a star-studded USA team outside Paris in September, he added: "Ideally, we would play this match tomorrow with the same 12 guys. Hopefully I will pull it all together and say the right things at the right time, get a team, get the best out of that team and get a winning performance".
Europe were beaten 17-11 on their last attempt to retain the trophy in the United States and, while McGinley believes it will be a tall order to do so this time around at Whistling Straits, he believes Harrington should have plenty of reason for encouragement.
Team USA has yet to announce its captain for the 2020 Ryder Cup.
But just because it seems like my turn, it's something I thought long and hard about.
Timberwolves 'rallying around' new head coach Ryan Saunders
It's already been a whirlwind of a season thanks to Sunday's firing of Thibodeau and the Jimmy Butler trade on November 12. However, Thibodeau was a driving force in bringing the Timberwolves back the playoffs after a 13-year dry spell.
Harrington can now begin his planning as Europe bid for their 10th victory in 13th contests since 2002, and the Irishman is relishing the challenge of retaining the trophy on a course he competed on in three PGA Championships.
But after missing out on automatic qualification for the first time in ten years, a few eyebrows were raised when Montgomerie, a previous Ryder Cup partner, chose him as the final pick for his 12-man side for Wales.
He was the first American to top the official world golf rankings in 1992 and was a two-time victor of the Ryder Cup as a player; featuring as a vice-captain in the 2012 edition took his total involvements to six.
Harrington is the third Irish golfer to hold the role since 2014. I think Thomas was blessed with the best team we've ever had in France. "I am very much looking forward to taking on this role".
"I have reached the stage in my career where I enjoy playing golf", Harrington said. I am putting something on the line going out there.
He said: "Steve's a solid bloke". The most important job a Ryder captain faces is to be liked and trusted by his players. "Good guy. Tough. Not a man to underestimate". He's as straight as they come.
Despite encountering abuse from the MA galleries for what they considered his slow play that day, abuse echoed by one TV commentator who suggested his deliberation "gave new meaning to the Boston Marathon", Harrington retained the mental resolve to beat O'Meara one up.