Chelsea have stepped up their pursuit of the Napoli striker Edinson Cavani, with the Italian club's president, Aurelio De Laurentiis, signalling both the Premier League club's interest and his own contingency plans to strengthen his squad.

Cavani has long been prominent on Chelsea's list of attacking targets, which also includes Fiorentina's Stevan Jovetic, Hulk of Zenit St Petersburg and Bayer Leverkusen's André Schürrle. José Mourinho, the Chelsea manager, is keen to upgrade his options and the club have opened talks with Napoli.

Cavani has scored 78 goals in Serie A since joining the club in July 2010, more than any other player in the league, and has a €63m (£54m) release clause in his contract, but Chelsea would not necessarily have to meet that. De Laurentiis would accept less for the Uruguayan, who has attracted the attention of other clubs, including Manchester City.

De Laurentiis confirmed Chelsea's desire to buy Cavani and said he had made an offer of €40m to Roma for their young stars – the defender Marquinhos and goalscoring winger Erik Lamela.

According to De Laurentiis, Roma offered to sell the striker Pablo Osvaldo but "seeing as, for now, we have Edinson Cavani, we don't need him".

"Chelsea are interested in Cavani and they will call me soon," De Laurentiis said. "I'm very happy that his brother [and agent] has said that he will stay, but if he did decide to go to Chelsea, we would take time out to think and replace him with people worthy of replacing him.

"I contacted Unicredit [the Italian bank which part-owns Roma] directly for Lamela and Marquinhos. I offered them 40m [euros]."

It promises to be a frenetic summer of player trading for Chelsea, and Mourinho is expected to offer some clues on Monday, when he faces the media for the first time since his return to the club.

Fernando Torres has described Mourinho's return as "great news" and does not believe it will affect his plans to stay at Stamford Bridge.

"I have three more years on my contract so I am not worried," the striker said. "I know my future is there. To be honest, it is like this every summer. There is talk and speculation. But as I said when I signed my contract I will be there for five and a half seasons. My future is there."

Torres said he can still "do better" for Chelsea. His form improved in the second half of the season under the interim manager, Rafael Benítez but he insisted that he had not changed anything in his training methods or mental preparation.

"I have been performing better because the team has been doing better," he said. "There is no secret."

The Premier League reported on Friday that Chelsea were set to release four members of the first-team squad that finished last season, plus Florent Malouda, who was frozen out and did not play at all.

The quartet are the goalkeepers Henrique Hilário and Ross Turnbull, the defender Paulo Ferreira and the midfielder Yossi Benayoun.

With Thibaut Courtois expected to extend his loan with Atlético Madrid into a third season, the departures of Hilário and Turnbull appear to leave Chelsea short in the position, withonly Petr Cech. It is clear Mourinho will need to add goalkeeping cover but there is still the chance he could offer Hilário a new contract.

Chelsea will not confirm which players from the Premier League's list will be released until the end of the month, when their contracts officially expire and, as such, they retain the capacity to open negotiations with those they chose over new deals. Hilário, whom Mourinho brought to the club in 2006, could yet benefit.