Arsenal boss Arsene Wenger has bemoaned his side's "very disappointing" performance in Sunday's 2-1 defeat against Bournemouth at the Vitality Stadium.
The Gunners led early in the second-half through Hector Bellerin, but were pegged back by Callum Wilson's 70th minute equaliser and conceded again moments later when Jordan Ibe struck.
And Wenger has admitted that his side lacked the required intensity and creativity to get the better of their hosts.
"Overall it was a tough game for us," said the Frenchman - quoted by Football.London.
"We were 1-0 up and then we made two very surprising mistakes. They weren’t forced errors, just lack of decision making.
"We come out of the game and think how did we lose.
9 - Arsenal have dropped nine points from winning positions in their last five Premier League matches alone. Careless.— OptaJoe (@OptaJoe) January 14, 2018
"If Sanchez goes, we need to replace him," said Wenger. "When you look today we missed many players today. If he goes, we have to respond.
"At the moment we try to use players who are completely focused on the club."
On the potential transfer, he added: "I
"I’m not concerned about the spirit," he said. "I’m concerned when it matters we are not dangerous enough."
Arsenal are now five points behind both Liverpool and Tottenham, who sit in fourth and fifth respectively in the Premier League standings.