Jose Mourinho insisted the pressure will be on Manchester United and, in particular, Liverpool to deliver in the campaign ahead as he reflected on a summer of lavish spending by his leading Premier League rivals and braced himself for a quintet of clubs to challenge for the title.

Chelsea continue their pre-season build-up with a friendly against Feyenoord in Rotterdam tonight having added four players to the first-team squad, only one of whom commanded a fee, the €20.2 million winger Florent Malouda. That approach contrasts starkly with the €74.5 million spent to date by both United and Liverpool and, while he conceded Alex Ferguson's options have been bolstered, Mourinho risked aggravating his already strained relationship with Rafael Benitez by claiming the onus will be on the Spaniard to secure the Merseysiders' first league championship since 1990.

"You could say the pressure is a bit higher [ on Liverpool] because, at this moment, they cannot point at other people," said Mourinho.

"In other years they could say: 'Oh, these guys, they've spent a lot of money so they have to win.' This season they have to talk differently. They have high responsibilities and high expectations.

"In the last three years it's been Chelsea and Manchester United in the league, and it's been a long time since Liverpool won the Premiership. So they really want it. I heard something earlier this summer - [ Steven] Gerrard, [ Jamie] Carragher and [ John Arne] Riise saying it has to be this season. That's normal, and positive. I cannot complain about that. Everybody wants to achieve it. We want it too, no problem.

"But it's been four years with Benitez and they want the Premiership. They don't hide it - Benitez, the players, they all speak about winning the title. I think winning nothing last season was frustrating for them, but they've got a good squad and good players, so they'll be better."

Mourinho backed his own players to regain the title, but added Tottenham could yet prove their pedigree and mount a sustained assault on the league. "It's just a personal opinion."

Meanwhile Claudio Pizarro last night confronted the reality of having to dislodge either a 33-goal striker in Didier Drogba or the 44 million forward Andriy Shevchenko to hold down a place in Chelsea's first team, but insisted he could be the player to "make a difference" as his new team-mates attempt to regain the Premier League title.

The 28-year-old forward trained with the senior squad for the first time yesterday since completing his free transfer from Bayern Munich, having been granted time off after involvement in the Copa America with Peru. Pizarro boasted 70 goals in 174 Bundesliga appearances with Bayern having previously played with Werder Bremen.

He is confident he can force his way into the first team.

"It'll be hard, of course, because Drogba and Shevchenko are good players who have scored many goals," said Pizarro. "And I'm not a player who has scored 30 or 20 goals in a season - I could, but it depends upon how we play and what the trainer wants from me. I know about the pressure. I have experienced big competition before."

Mourinho had been anxious to add more firepower, especially because of Drogba's expected involvement in next year's African Cup of Nations.

"I'm convinced he will be a success," said Mourinho. "He's intelligent and holds the ball up well."