Brazilian midfielder Willian and Cameroonian striker Eto'o both made the move from Russian club Anzhi Makhachkala late in the summer transfer window but will have to wait for their Premier League debuts after joining following a tough pre-season campaign at Stamford Bridge.
"You speak to them and they talk about how the intensity of their training is a lot different to how it is here so for sure it will take them a few weeks to get their full fitness," he told ChelseaTV.
"But once they do they'll both look very good. I said to him (Eto'o), 'Thank God you're here', because I've had so many battles against him.
"He's such a threat, he's obviously a few years older but he still looks very sharp and hungry.
"He's got an eye for goal and I think he'll be a good addition. He was welcomed straight into the squad."