Olazabal, who teamed with Ballesteros as the most successful pairing in Ryder Cup history, broke down as players honored Ballesteros with a minute's silence at the Spanish Open, hours after the 54-year-old golf great died of brain cancer.
Olazabal and fellow Spanish player Miguel Angel Jimenez both wept during the somber silence, the pair comforting each other with a long embrace. They then went out and played the third round as best they could.
"I just played the most difficult round of my life. It was very tough to make it to the first tee and hit the first drive," said Olazabal, who shot a 3-over 75.
"I didn't doubt about playing today. The last thing he would have wanted would have been for me not to play. I don't think there will ever be another player like him. There can be others that are very good, but none will have his charisma."
The 45-year-old Olazabal, a two-time Masters champion, choked up while answering reporters' questions about Ballesteros.
"Obviously, he has been present all the time," he said. "Our relationship was so close. I always felt privileged for all the moments that we shared together, and there have been many. Even though I knew what the situation was, when the moment arrives you are never sufficiently prepared."
Playing partner Colin Montgomerie said Olazabal was "in floods of tears most of the day. He has lost an older brother almost."
"It was very difficult to get too much out of Jose Maria -- he was very tearful and filling up. You could see in his eyes the great loss he feels and they've been a great support for each other. He did well to play at all today," said Montgomerie, who partnered with Ballesteros in a number of Ryder Cups. "It was his brother, really. It was a very, very sad day for him."
Olazabal lauded the strength and "fighting spirit" of the five-time major champion, who he knew was ailing after their last meeting April 16.
"He wasn't well but he was lucid. We spoke about a lot of things and memories of the Ryder Cup," he said.
Olazabal sported a small black wreath on his baseball cap that many other players and club staff wore on their lapels to honor a player who won a record 50 times on the European Tour.
Flag pins were kept at half staff on a day with an overcast sky and chill in the air. One fan embraced Olazabal as he made his way to the clubhouse.
Olazabal, who will captain the European Ryder Cup team across the Atlantic in Medinah next year to become the second Spanish captain after Ballesteros, recalled his first meeting with an idol turned friend nearly 30 years ago.
"I was an amateur and he called me to play a charity match. He surprised me very much and I was very excited about it," Olazabal said. "I have lived so many moments with him so it's hard to pick just one but, without a doubt, the moments of the Ryder Cup, especially '97."
That was the year Ballesteros captained Europe to victory on Spanish soil at Valderrama, a special moment for Jimenez.
"I was his assistant; it was a very special week. Seve's passion for the Ryder Cup was one of a kind," said Jimenez, who raced from the 18th hole to reach the minute's silence in time. "The thing that really stands about him is his determination, his tenacity and his passion for everything that he did."