Sometimes he is an established junior tennis star. At other times, like this weekend in Rogers Cup qualifying, he is a rookie trying to find his way at the professional level.
"It's obviously important to adjust when you're playing juniors or pros," said Peliwo. "I'm going from being one of the favourites to being a big underdog."
The 18-year-old North Vancouver, B.C., native will begin his qualifying attempt on Saturday. His opponent was to be confirmed late Friday night.
The suspense added just another chapter to Peliwo's transition from the junior ranks to the pros — in the same season. Peliwo must win both of his qualifying matches to get into the main draw.
It's a much different situation than in July, when he became the first Canadian to win the Wimbledon junior men's championship.
He joined an exclusive Wimbledon junior champions group that includes Swiss ace Roger Federer, who withdrew from the Rogers Cup on Friday.
"Definitely, (the Wimbledon victory) improved my confidence a lot," said Peliwo, "Obviously, it doesn't really translate into a pro career as much, because it's a different game out here."
Peliwo also reached the finals of the Australian Open and French Open earlier this year. He is ranked No. 2 in the world at the junior level and 620th among men. He briefly held the No. 1 junior men's ranking, again becoming the first Canadian to do so, after his Wimbledon triumph, but was overtaken recently by European champion Kimmer Coppejans of Belgium.
However, the thrill of victory at the junior level has been offset by a number of disappointments in pro matches. On Tuesday, he lost in the first round of the Odlum Brown Vancouver Open, a $100,000 Challenger tour event in West Vancouver, B.C., falling 7-6 (4), 6-0 to journeyman pro Jimmy Wang, 27, of Chinese Taipei.
Peliwo battled in the first set as he overcame a deficit of 4-2 in games and 4-0 in a tiebreaker, but admitted he lost his focus while being blanked in the second set.
Two weeks ago, he lost in the first round of a $50,000 Challenger event in Granby, Que. The match was closer, but the result the same as he lost 6-4, 7-6 (6) to unheralded 30-year-old Roman Borvanov of Moldova, the world's 265th-ranked player.
The attempt to qualify for the Rogers Cup will be no less gruelling.
"Honestly, it's going to be really tough," said Peliwo. "I'm going to have to play even better than I would (in the Odlum Brown). It's going to be, probably, the toughest tournament I've ever played."
But being a rookie pro among lesser-known pros and the game's biggest stars can also be beneficial at times. Peliwo feels less pressure when he competes against pros.
"It lets me play my game a bit more," he said, adding that it doesn't really change how he prepares for a match.
"I try to do the same thing as I would in the juniors and take every match the same way. The only difference is, the players here are much faster, much stronger. I've just gotta play better on a consistent basis," he said.
In the meantime, he sets his sights on more junior glory. Peliwo, who trains out of the National Tennis Centre in Montreal, hopes to excel in the junior segment of the U.S. Open in September. He will also play a few other junior events before he begins competing as a pro full-time.
Along the way, he will strive to stay on an even keel as he bounces from the top of the world to the bottom and back.
"I just try not to look in the past," he said. "I try to forget, well not forget about it, but put it behind me. I put Wimbledon behind me. I put the losses behind me."
Peliwo said he had two tough losses in the last two Challengers he has played.
"I'd have to play really well, so I'm not too disappointed about those losses," he added.
As he moves from favourite to underdog, he attempts to gather as much knowledge as he can from the struggles.
"I'm going to take what I can and learn from them — and hope for the best later on in my career," he said.
Note: Peliwo was one of four Canadians granted wild card status by Tennis Canada for Rogers Cup qualifying. The others were Erik Chvojka of Montreal, Steven Diez of Toronto and Pierre-Ludovic Duclos of Sainte-Foy, Que.