Manchester City were the favourites to sign the Chilean, but a late intervention from the 20-time English champions have seen them overtake their city rivals and are now certain to complete the signing of Sanchez in the coming days.
Arsene Wenger and Jose Mourinho confirmed that talks were taking place and that a deal was imminent with Henrikh Mkhitaryan expected to move the other way to the Emirates Stadium. City were forced to pull out of the deal after they refused to match United's financial package on offer which Sanchez has accepted - said to be around £14m ($19.4m) per season after tax and a £20m signing on fee.
Sanchez was said to have agreed to join the Etihad Stadium outfit before a late u-turn, which Guardiola feels could have brought about by his agent. However, the former Barcelona coach made it clear that he holds no grudges towards his former player and wished him all the best for his future with the Red Devils.
"I am not the guy with the mathematics, the numbers," Guardiola said when asked if it was United's financial package that made City pull the plug on the deal, as quoted on Sky Sports.
"What I know right now is Alexis is still an Arsenal player. I think he is going to go to United so congratulations to both of them," he added all but confirming the striker's imminent switch to Old Trafford.
"In the end, the players and managers decide where they want to play. Good luck."
"My opinion of Alexis remains the same," Guardiola said. "It was a pleasure to be with him at Barcelona and he is going to decide to move onto another club. I wish him all the best."
The City boss, however, did admit that he did not want to risk destabilising his squad by signing Sanchez and matching the wages on offer at United. Reports are suggesting that the Chile international will be paid around £500,000-a-week in wages by United, which is reportedly double that of the Cityzens' highest paid player Sergio Aguero.
"Normally we try to be stable with the wages of the players because I think it is good for the team and stability of the club," Guardiola said, as quoted by The Telegraph. "I've never put pressure on a club when they believe it is too much. Immediately I accept that decision and move forward to find another solution. The stability of the club is the most important thing."
"We've spent a lot of money, we can't deny that. But in my period at Barcelona, my period at Bayern Munich and now here, I never pushed or pressured the club to say 'I want those players' when the club believes and says it's too much. The stability of the club is the most important thing," he added.