LONDON: Alexis Sanchez will miss Arsenal's first Premier League game of the season after being given an extended break following his exertions with Chile at the Copa America.

Arsenal manager Arsene Wenger said Sanchez would return to the club at the start of August but would then need time to regain match fitness.

Sanchez will miss the Community Shield against league champions Chelsea at Wembley on Aug. 2 as well as the league opener against West Ham United the following week after a gruelling Copa America campaign.

The athletic forward scored the winning penalty for his country in the Copa final against Argentina on July 4 in his 58th game of last season.

"Alexis will be back on Aug. 3. Usually it takes three weeks to be competitive. With Alexis it could be a bit less. He will miss certainly the first game," Wenger told a news conference in Singapore.

"He is an important player for us and he showed he has the winning mentality when he took on the responsibility to take the last penalty in the Copa America final against Argentina."

The 26-year-old Sanchez became a pivotal figure in Arsenal's campaign last season, helping them put a superb run of results together in the second half of the campaign.

Their hopes of sustaining a credible title challenge this season have been given a boost after they managed to persuade Chelsea to allow keeper Petr Cech to join one of their direct rivals.

"It’s true not many players leave Chelsea for Arsenal, but the deal itself was not too difficult," Wenger said.

"The decision was difficult because I felt our two goalkeepers did very well last season, but, on the other hand, we could add experience and strengthen the belief of our squad."

Goalkeeper has long been a problem position for Arsenal with David Ospina and Wojciech Szczesny both culpable for errors last term as the side finished third.

Cech's arrival has been greeted warmly by Germany international Per Mertesacker, who will be marshalling the defensive line in front of the Czech shot stopper.

"There’s even more belief now and we feel very confident at the back. There are many doubters out there, but we feel a lot stronger with Petr Cech," he said.