"The Porto footballer is prevented from joining the squad due to the protocols and sanitary regulations established by local authorities in Portugal," read an FCF statement.
Their Canadian forward Christophe Lalancette completed his hat-trick in the final stretch to guide his team to a respected victory and the first place in the rankings, 4-5.
Lo Celso did not train with his Albiceleste teammates on Monday after failing to recover from the muscle strain that kept him out of Tottenham's 6-1 victory at Manchester United on Sunday.
Edmond Tapsoba (R) of Leverkusen vies with Silas Wamangituka of Stuttgart during a German Bundesliga match between VfB Stuttgart and Bayer 04 Leverkusen in Stuttgart, Germany, Oct. 3, 2020. (Photo by Philippe Ruiz/Xinhua)
Ajax had more possession and more chances in the first half, but it was Groningen that found the net after the restart. Ajax goalkeeper Andre Onana stopped a shot from Groningen striker Jorgen Strand Larsen, but he had no answer to the rebound from 19-year-old forward Remco Balk.
American Sara Hall, who sprinted to surpass world champion Ruth Chepngetich in the last meters, finished second in 2:22:01. Chepngetich from Kenya completed the race four seconds later.
Although it is still very early days, the signs are much better at FC Barcelona than many expected before the season started. Ronald Koeman's team has won its first two games with ease, netting a total of seven goals without conceding and the image on the pitch has been much better than the side that looked sad and tired during Quique Setien's time in charge.
Stan Wawrinka of Switzerland in the men's singles match at French Open 2020 in Paris. (Photo by Aurelien Morissard/Xinhua)
The "BVB" controlled possession and should have added another goal to its lead before the break but Freiburg's goalkeeper Florian Muller was on guard to defuse the efforts from Thomas Meunier and Mats Hummels in the closing period of the first half.
The 19-year-old Pole needed just 68 minutes to avenge her exit to the 2018 champion last year in Paris at the same stage.
Gaston is to challenge third seed Dominic Thiem in the fourth round. Earlier in the day, the Austrian had claimed another straight-sets victory over 28th seed Casper Ruud, beating the Norwegian 6-4, 6-3, 6-1.