Arsenal manager Arsene Wenger expects Alexis Sanchez to "respect" his decision not to allow the Chilean forward to leave the club, he said on Thursday.
"I will not give anything away on (Sanchez), but the only thing I can tell you is that he is focused and my decision is clear: he will stay and he will respect that," Wenger told reporters.
"It is as simple as that."
Sanchez, 28, has been linked with a move away from Arsenal during the close season, with Manchester City and Paris Saint-Germain reported to be among his suitors.
He was given an extended break after playing for Chile at the Confederations Cup in Russia and his return was delayed last weekend due to illness.
Having eventually returned on Tuesday, he took part in an open training session at the Emirates Stadium on Thursday ahead of Sunday's Community Shield showdown with Chelsea at Wembley.
With Sanchez's Arsenal contract set to expire next year, the speculation about his future will not go away, but Wenger refused to divulge information about the contract talks.
"Every negotiation has to be a little bit secret," Wenger said during a press conference.
"The transparency of society is very pushy, but we have to resist a little bit, as much as we can.
"We know as well we have a duty to inform people, but to talk about some things is not information any more -- it is suicide.
"I think he will be here this season and if we can do it for more seasons, we will do it as well."
Wenger said there was "nothing to announce" regarding the futures of Mesut Ozil, Alex Oxlade-Chamberlain, Jack Wilshere and Kieran Gibbs, who are also out of contract next year.
But he did say that he expects Spanish striker Lucas Perez to leave after a frustrating debut season.
Perez joined Arsenal from Deportivo La Coruna a year ago, but barely featured last season and now faces extra competition from star signing Alexandre Lacazette.
Asked if Perez's future lay elsewhere, Wenger replied: "Yes, because we have a congestion of strikers.
"I don't like to lose him because, for me, he's a top-quality striker, but we have many strikers. At some stage, too much competition is not competition any more.
"You cannot give the chance to everybody, so if he finds a satisfying solution at least for a short time, he will do it."
Sanchez, Wilshere and Shkodran Mustafi are all short of fitness, having only just returned to training.
Francis Coquelin will definitely miss out against Chelsea after hurting his ankle in Arsenal's friendly against Benfica, while Gabriel and Santi Cazorla are long-term absentees.
But Lacazette and fellow new signing Sead Kolasinac are both expected to feature against the Premier League champions.