The Blues have only brought in striker Demba Ba from Newcastle this month despite being linked with a host of names, including the likes of Shakhtar Donetsk midfielder Willian and Atletico Madrid forward Radamel Falcao.
Despite refusing to name any potential targets, the Spaniard hinted that he is still looking to bring in reinforcements before 1 February in order to give some of his over-worked players a much-needed rest.
“We cannot rest too many players because our squad is not that big in certain positions,” said the Chelsea interim boss.
“I had a good conversation about this with the owner the other day. I gave my opinion, he listened to me. But I have to concentrate on the team.
“I have to play Frank Lampard and Ramires all the time because we have problems with injuries and suspensions and we have two players at the Africa Nations Cup.
“We have had nine games a month since I came here and the players are a little tired. You can really see the difference when players are allowed to have a rest.”
Chelsea travel to League One side Brentford in the FA Cup fourth round on Sunday afternoon.
Betfair are offering new customers enhanced odds of 6/1 on Chelsea or 10/1 on Man United to win Sunday's game. Click here to sign up now.
MORE: The latest football news