Chelsea chief executive Ron Gourlay has said that he is "expecting the introduction of two or three new players" at the club in the summer, ahead of their pre-season tour of Asia.
The Blues signed four players last summer including Eden Hazard and Oscar, but their defence of the Champions League ended in the group stages and the club are currently fourth in the Premier League.
"When you look at the last three or four transfer windows, we have continued to invest in the team and the philosophy of the football club is based on success on the field," he told the club's official website.
"We will continue to strength the team and I am expecting the introduction of two or three new players and hopefully they will be in place in time to be part of the team in Thailand."
Chelsea have denied that they are in talks with midfielder Frank Lampard over a new contract.