No deal has yet been secured with the Serie A champions, though, and Planes was unwilling to give too much away on the Uruguay star's future at the presentation of Miralem Pjanic on Tuesday.
"He has been – and is – an important player for Barcelona in recent years and for that reason deserves maximum respect," Planes said.
"Following the end of the season, we're in a process of change, changing the coach, ideas... But we have to respect the players and their contracts. Until October 5, when the [transfer] window closes, anything can happen."
There were reports in Depay's homeland on Tuesday that a deal to bring him to Camp Nou for an initial €25million was in place, although counterclaims in Spain have denied such an agreement.
Planes made it clear the Catalans are looking for attacking reinforcements, saying: "It's been public for months that we're working on improving the team, looking for players of quality and experience, because not just any footballer can play for Barca.
"Among them, we're looking for a forward, but that's not dependent on the departures of players in the squad now. We always aspire to have the best possible squad."
Planes also admitted interest in Manchester City defender Eric Garcia, who is in the final year of his contract at the Etihad Stadium and will not be renewing.
"We are looking for players to help in defense and Eric's a good player, he developed here," Planes added.
"We want to build a team that mixes talent, quality and youth, and Eric fits the profile we want and we're looking into it, but there are also other names being followed that haven't come out in media."