Back in 2005, when Nadal's remarkable 14 titles on the Parisian clay were still in the future, the German faced the Mallorca native in the first round.
Burgsmuller, then aged 29 and the world number 96, lost 6-1, 7-6, 6-1, but pushed 18-year-old Nadal to a tiebreak in the second set.
The German, who had already played Nadal the year before at Indian Wells when he was just 17, losing 6-2, 6-3, told AFP he "was not so enthusiastic" when he found out who he would face.
"Let's just say I'd heard from all sides that he was the next big thing," Burgsmuller, 47, said from his home in Essen, where he now works as a radiologist.
"Of course, at such a big tournament you hope for an easier draw, especially at the beginning.
"At the moment when I lost the match, you can see why I wasn't so excited."
The German said that while he was disappointed with the outcome at the time, he realised he was witnessing something special in the making.
"You have to acknowledge without any envy that he just somehow plays in another league," Burgsmuller said.
He counts the memory alongside his matches against Roger Federer and his Wimbledon clash with Andre Agassi as career highlights, alongside his win at the ATP event in Copenhagen 2002.
In the 17 years since their meeting, Nadal has amassed those record 14 French Open titles and lost only three of 115 matches.
Although he was convinced of the Spaniard's talent, he admits to being surprised Nadal went on to win the tournament at his first attempt.
"I felt that he was playing well and would have a great future, but that he would go from 0 to 100 so quickly and win the French Open, I honestly did not expect that.
"I don't know if he expected it himself or if anyone else did."
Burgsmuller said Nadal gave "full throttle" from start to finish in their match.
"It makes no difference whether it's 0:0 or later on... he plays the first ball just like the last ball.
"You have the feeling you have to win every rally three times to get the point.
"I caught myself in moments where I thought 'OK, I've got the point', and then somehow he gets it past you -- and it really hurts you.
"That's his strength, even from difficult situations from the corners to somehow hit fantastic balls anywhere on the court."
'Beyond the pain barrier'
Nadal's powerful game has carried him to a record 22 Grand Slam titles, equal with Novak Djokovic, but it has also taken a punishing toll on his body.
The Spaniard told reporters on Thursday his inability to recover from a hip injury in time for the French Open was "not a decision I made, it's a decision my body made."
"I need to stop for a while."
Like Nadal, Burgsmuller also battled injuries in his career and has followed how the Spaniard has faced setbacks along the way.
As a doctor, Burgsmuller said "you can certainly say that it does not make sense" to play through injury pain, but it was "ultimately up to the athlete to decide".
Burgsmuller said he hoped Nadal would still add to his French Open total in his final appearance next year, but feared the ongoing impact of injuries put that out of reach.
"It's never nice to see someone who is somehow battered and injured, who needs to push themselves beyond the pain barrier -- someone who is on the verge of maybe giving up or not even competing.
"A two-week Grand Slam is already incredibly exhausting for the body."
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