The Gunners came close to signing Lemar towards the end of last summer’s transfer window, only for the deal to fall through at the last minute.
Their interest has since waned while Liverpool have been strongly linked with a move to bring him in as Philippe Coutinho’s replacement.
Monaco have previously stated they have no interest in letting Lemar leave this month, but it has since been suggested a big-money offer could tempt the Ligue 1 into selling up.
And with Sanchez constantly linked with a move to Manchester City, Arsenal are prepared to enter the race once again to sign Lemar.
That’s according to the Mirror, who claim Pep Guardiola’s side are willing to pay as much as £30million to sign Sanchez.
And if that deal goes ahead this month, the Gunners will look to fast-track a deal to sign Lemar under the noses of Liverpool.
Lemar rose to prominence last season and played a vital part on Monaco’s title-winning campaign as well as putting in a number of scintillating performances in the Champions League.
And Monaco manager Leonardo Jardim recently hinted Monaco could be tempted into selling for the right price.
“We do not typically sell players in the winter transfer window,” Jardim said.
“But the month is long and many things could happen.”