Manchester United's 2003-04 season was a curious transition in Sir Alex Ferguson's tenure that felt simultaneously rich in talent and frustratingly incomplete.

The job Ferguson did in rebuilding his squads over and over was genuinely extraordinary, and the 2003-04 group was a blend of two different versions of the legendary Scot's United.

Ryan Giggs, now entering his second decade at the club, remained one of the most dangerous wide players in Europe, and Paul Scholes was arguably at his creative peak, but the summer transfer window had been dominated by David Beckham's departure to Real Madrid.

The teenager who arrived in place was none other than 18-year-old Cristiano Ronaldo. He scored six goals that season and was hailed by Ferguson as a "new hero" for the club. Few could have imagined quite how right that would prove to be, but he was not nominated by the manager as the key man that year.

Roy Keane captained the side and was the heartbeat of everything United did, while Rio Ferdinand's absence in the second half of the season due to an eight-month ban following a missed drugs test proved hugely damaging.

Up front, Ruud van Nistelrooy was one of the most lethal finishers in world football, but his season will forever be tied to one moment: his penalty against Arsenal in September 2003, which crashed against the bar and allowed the Gunners to escape Old Trafford with a 0–0 draw, as they went on to win the title as Invincibles.

A bittersweet season that showcased some of the finest players ever to pull on the red shirt, then, but it was none of those legendary names that Ferguson picked out as his "star of the show".

Sir Alex Ferguson praises USA legend

Indeed, it was American goalkeeper Tim Howard who Ferguson said was their most important man that year.

Having lost patience with Fabien Barthez, Sir Alex signed Howard from what is now the New York Red Bulls in the summer of 2003 for a $4 million transfer fee (£2.3m).

The manager later revealed he didn't expect Howard to be as good as he was, hailing him as the club's best player that campaign, speaking in January 2004.

Howard would play 44 times that season en route to an FA Cup triumph, beating Millwall 3-0 in the final in Cardiff, and was named in the PFA Team of the Year.

Having struggled the following campaign, Howard was replaced by Edwin van der Sar in the summer of 2005, and went on to join Everton in the summer of 2006.

It was there he cemented himself as one of the most consistent shot-stoppers in world football, and as a stalwart between the sticks for the US Men's National Team.

Howard broke the record for saves in a World Cup match

In the 2014 World Cup Round of 16, Howard set the record for the most saves by any goalkeeper in a game in World Cup history, denying Belgium 16 times in a 2-1 defeat.

“I don’t have the words to do justice to his performance,” said Everton teammate Romelu Lukaku, while USA coach Jurgen Klinsmann added: “Tim was just phenomenal.”

Now the most-capped goalkeeper in USMNT history, Howard will be hoping current number one Matt Turner can produce his own miracle performance this summer.