Arsenal are hoping to beat Everton to the £17m signing of Deportivo La Coruna striker Lucas Perez Martinez.
Everton had identified the 27-year-old, who scored 17 goals in La Liga last season, to provide support for Romelu Lukaku.
The Toffees were closing in on a deal – but Arsenal have now declared a late interest in the striker known as Lucas.
Everton are still hopeful of a deal but reports in Spain suggest Arsenal are strong favourites to sign the player.
It would be a disappointment for Everton manager Ronald Koeman and director of football Steve Walsh, who is a long-time admirer of the Spaniard.
Everton have also been linked with Napoli’s Manolo Gabbiadini.
Wenger is looking to make a breakthrough in the transfer market and insisted he was not reluctant to spend after being criticised by Arsenal fans during and after the goalless draw at Premier League champions Leicester City on Saturday.
Koeman, meanwhile, is determined bring in another striker as support and competition for Lukaku, who had been strongly linked with a return to former club Chelsea but has now decided to stay at Everton.
Everton have an offer on the table for Sunderland’s unsettled central defender Lamine Kone which has so far been rejected by Black Cats’ boss David Moyes, while Koeman also wants to sign a goalkeeper.
The possibility of Joe Hart arriving on loan from Manchester City is being complicated by the possible £7m cost of a potential season-long loan, with Hart on a reported £135,000-a-week and a loan fee also being involved.
Subscribe to the BBC Sport newsletter to get our pick of news, features and video sent to your inbox.