“We wish Jason well and hope his back recovers quickly. We were eager to have Jason as part of the team at Royal Melbourne and his experience will be missed,” Els said.

“The good news is that there were a number of strong and qualified players available to choose from when I made my captain’s selections. To have someone as steady and talented as Ben An puts us in a great position to succeed. Ben played extremely well this fall and throughout the year and he will fit in nicely on this team.”

An was third at the Sanderson Farms Championship and added top-10s at THE CJ CUP @ NINE BRIDGES (T6) and ZOZO CHAMPIONSHIP (T8). He also finished T14 at the World Golf Championships-HSBC Champions and sits 16th in the FedExCup after the fall series.

While An is winless in his 103 PGA TOUR starts the 28-year-old has three runner ups and has match play pedigree as the youngest ever winner of the U.S. Amateur – taking out the 2009 title as a 17-year-old.

“I’m sorry to hear that Jason has been forced to withdraw from the International Team and I wish him a speedy recovery. It was a huge surprise to receive a call from Ernie who told me that I was in the team,” An said.

“It has been a goal of mine all season to be on the International Team and I am honored to play in my first Presidents Cup. I’m looking forward to joining Ernie and the rest of the team in Melbourne and, more importantly, contribute to the International Team’s goal to win the Cup.”

An’s selection brings the average age of what was already the youngest Presidents Cup team in the events history further down to just under 29 and gives Els seven rookies in his 12-man squad.

Only once before has the International Team had seven newcomers – in 2013 at Muirfield Village. Coincidentally current team members Marc Leishman, Louis Oosthuizen and Hideki Matsuyama were three of those debutants in Ohio and might be able to impart some wisdom to their teammates.

With the U.S. team holding a 10-1-1 advantage overall in the biennial contest perhaps new blood is exactly what the Internationals need.

“I'm here to try and win enough points to get us over the line, and that's what the players' mission is, is to try and get enough points to get the Cup back. If that’s off the back of the rookies, so be it,” Els said earlier this month.

Meanwhile, the injury is worrisome for Day, who is winless since early 2018 and managed just one top-10 finish after the Masters last season. In his last start in Mexico – which came right after Els plumped for him as a captains pick - Day was out of sorts and missed the cut.

The 32-year-old has a history of back problems that have hindered him throughout his career.

“I’m quite disappointed I won’t be coming home to play in either the Australian Open in Sydney or the Presidents Cup the following week in Melbourne,” Day said via a statement.

“I was quite looking forward to both events. I had been prepping all week in Palm Springs when I was injured. Frustratingly, I’ve been through back problems before and my medical team decided it best to shut down all practice and play.

“Therefore, I wanted to inform Golf Australia as well as provide Ernie as much time as possible to best prepare our International Team for Royal Melbourne. I look forward to playing at home in the near future. My best to all the competitors in Sydney and my teammates in Melbourne.”

Day did not elaborate on his recovery period but it is likely he won’t return before the Farmers Insurance Open on Jan. 23-26 where he is a two-time champion.