MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay plays a forehand against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay plays a forehand against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay plays a forehand against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay plays a backhand against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay reacts against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay plays a forehand against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Adolfo Daniel Vallejo of Paraguay plays a forehand against Juncheng Shang of China during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)

MONTREAL, CANADA - AUGUST 02: Miomir Kecmanovic of Serbia plays a backhand against Michael Zheng of the United States during their singles first round match on day one of the ATP 1000 National Bank Open presented by Rogers at Stade IGA on August 2, 2026 in Montreal, Quebec, Canada. (Photo by Minas Panagiotakis/Getty Images)