José Mourinho has stated that Wayne Rooney is Chelsea's only remaining summer transfer target, with the club having no contingency plans should Manchester United resist selling the striker.

Chelsea have had a £20m straight cash offer rejected for the 27-year-old, who is also of interest to Arsenal. Arsène Wenger, who is keeping his options open on Liverpool's Luis Suárez and Gonzalo Higuaín of Real Madrid, said that Arsenal could afford to pay Rooney, despite him earning £250,000 a week.

Wenger also indicated that United might be disappointed in their attempt to sign the former Arsenal captain Cesc Fábregas from Barcelona. United have had a £26m bid turned down and Wenger, who has a good relationship with Fábregas, said that he believed the midfielder would stay at the Camp Nou for another year.

Chelsea reacted angrily to the suggestion from United that their opening offer for Rooney had included the option for the Premier League champions to take either Juan Mata or David Luiz as a makeweight. They went as far as to release a statement that confirmed their offer for Rooney but hinted at their frustration that, first, the move had been made public and, second, the part-exchange had been mooted.

"Chelsea can confirm that it made a written offer to Manchester United for the transfer of Wayne Rooney," a club spokesman said. "Although the terms of that offer are confidential, for the avoidance of doubt and contrary to what is apparently being briefed to the press in Sydney [where United are on tour], the proposed purchase does not include the transfer or loan of any players from Chelsea to Manchester United."

Mourinho insisted that Chelsea had behaved in a "proper" and "ethical" way and that their conduct had been "clean". "The situation now is clear," said Mourinho, after his team had beaten the Singha All-Stars 1-0. "Chelsea is interested in the player. Chelsea made an official bid. What we did, we did officially, between our club and Man United. We have nothing more to say. You have to respect Man United and you have to be ethical in this process. So no more problems.

"We don't want to make public what has to be private, which is the official bid we made. The official bid is about a certain amount of money; [it] doesn't involve players and does not involve the players in the possibility of the negotiations. There are none involved in the deal. Not Juan Mata. Not David Luiz. I have to finish the story. The club knows we want the player. The player has to know we made a bid for him. Now it's up to them."

Mourinho was asked whether Chelsea had bid for any other player. "No, and we won't," he said. It was subsequently put to him that it must be Rooney or bust. "Yes," he said.

United not only rejected Chelsea's offer, they made it clear that they would not sell him to a direct rival. But Wenger, who lost Robin van Persie to United last summer, is open to taking Rooney and exacting a measure of revenge. "It happened to us," he said. "It can happen to them."

Wenger, who revealed that the club captain Thomas Vermaelen would be out for "two months at least" with a stress fracture to the back, said he was "not specifically after one name" on the market. "We have not the problem of the wages of Wayne Rooney but it's very difficult for us to talk about any specific case. We work well but we are not close to sign anybody. The competition in Europe is very hard at the moment. There's a lot of money and not many players."

Arsenal negotiated a clause in Fábregas's contract when they sold him to Barcelona that gave them first refusal should he leave. Wenger suggested that they would be interested in him but he does not envisage it becoming an option. The Barcelona manager Tito Vilanova wants to keep Fábregas but it is understood that the club's board would be open to offers.

"Fábregas has decided to stay one more year at Barcelona," Wenger said, after Arsenal's 7-1 win over a Vietnam XI in Hanoi. "Unless he has changed his mind, I don't know … but that's what I've been told. We have the clause in the contract so we would be on alert but at the moment that's not something we're after."

United's insistence that Rooney is not for sale is complicated by the player's desire to leave, with Chelsea believed to be his favoured destination. Rooney is unhappy with his drop down the pecking order at United and he was described as "angry and confused" after David Moyes appeared to suggest that he would play second fiddle to Van Persie. Moyes did not intend any slight. Rooney is likely to have to submit a transfer request to force a move.

Ed Woodward, United's executive vice-chairman, has left the tour in Sydney to return to Europe to attend to urgent transfer business. The club have an interest in David Luiz, together with Everton's Marouane Fellaini and Leighton Baines but the top target is Fábregas. Moyes's Old Trafford debut comes on 26 August against Chelsea.