Manchester United executive vice-chairman Ed Woodward has described the pursuit of summer signings as "relentless".
Woodward has been instrumental in bringing Matteo Darmian, Memphis Depay, Morgan Schneiderlin and Bastian Schweinsteiger to Old Trafford this transfer window.
The 20-time league champions are still looking to strengthen their squad before the season starts, and Woodward admitted that a shortlist is drawn up for every position targeted.
He told MUTV: "Louis [van Gaal] sets his targets – and I think it's always important to have more than one for each position, because you have to accept that sometimes you may not get your first choice for whatever reason.
"It's relentless because you're immediately focused on the next [signing]. To that extent, I am completely aligned with the fans. When we tell them we've signed a player, there is a moment of happiness but then it's about who's next."
United are currently on tour in the United States, playing in the International Champions Cup.