The highest-ranked Japanese player ever on the ATP tour, Kei Nishikori was under tremendous pressure to finally crack the Top 45 for the first time, his coach recalls.

Before he did so in 2011, Nishikori was billed as “Project 45” and many talked about whether he could set a new high ranking for Japanese men. His coach, Dante Bottini, recalled that in the summer of 2011, Nishikori was ranked No. 46 but then dipped to No. 60. He finally broke through in October, reaching the semifinals at Shanghai to get to No. 30.

“That was a nightmare,” Bottini told the Washington Post. “Especially for him, he was having such a hard time. You could tell he felt the pressure so much. It was always, ‘If you win this match, you’re going to break the Project 45’—boom. He was 6-2, 2-0 up—boom, he loses 7-6 in the third. In the final, against this guy he should have beat—boom, choked so bad, lose. It was a nightmare."

But Nishikori has moved up ever since, noted the coach, saying, "He got past it, and then he really got past it.”

Nishikori is currently ranked No. 4, having just won the Citi Open in Washington. Last season, he reached his first Grand Slam final at the U.S. Open, losing to Marin Cilic. Nishikori topped Cilic in the semifinals last week in Washington. The 25-year-old has yet to win a major, but Bottini says that Nishikori could someday reach No. 1.

“I’m not saying that is going to happen this year,” Bottini said. “That is one of his goals for sure.”

Michael Chang is also coaching Nishikori.