If Nadal wins, it will be perfect symmetry for the tournament organisers and the 30-year-old. At the start of the tournament, Nadal attended a ceremony in which the centre court was named after him.
Rewind 12 years on the same spot and it was was an 18-year-old Nadal who won in Barcelona for the first time seeing off his compatriot Juan Carlos Ferrero 6-1 7-6 6-3. Nadal went on to win his first Grand Slam tournament at the French Open that June.
The following year, 2006, Nadal defended his title in Barcelona at the expense of compatriot Tommy Robredo 6-4 6-4 6-0 and proceeded to Paris to retain the French Open.
Over the past decade or so, Nadal has been the king at the Real Club de Tenis Barcelona. He hasn’t done too badly either at Roland Garros in Paris or at the Monte Carlo Country Club where he has won nine and 10 times respectively.
With last week’s victory in Monte Carlo, he became the first man to win a tournament 10 times since 1968 – the so-called Open era in which professional players have been allowed to participate in events.
Thiem – a semi finalist at last year’s French Open - reached Sunday’s final following a three set win over top seed Andy Murray.
Thiem, seeded fourth, fired 41 winners and six aces as he recorded his first win over Murray at his third attempt
"It's the first win over a world number one so it's really something special," said Thiem. "But it's also the first win over a top 10 guy this season. There are many positive things to take from the match.
"For me personally, it's the best victory this year so far. I went down in the third set when he broke me in the first game. But the way I came back mentally was a huge step forward."
The Austrian is one of the few people who has beaten Nadal on clay. The victory came at the Buenos Aires Open last year when Thiem held his nerve to claim the final set tie-break.
Nadal advanced to Sunday’s showdown with a 6-3 6-4 win over Argentina's Horacio Zeballos. Despite the straight sets victory, Nadal said he was far from pleased with his week's work in the Catalan capital where rain has made the conditions heavy.
"In weeks like this, the one who manages to cope with the conditions we've had, which have been significantly different than normal, is the one that survives.
"They aren't the best conditions for me and against Zeballos it wasn't easy at all. He took me out of my comfort zone, particularly in the first few shots of the rally."