Chelsea will be looking to extend their unbeaten run Getty Images/ADRIAN DENNIS

Chelsea playmaker Oscar says summer signings Diego Costa, Cesc Fabregas and Filipe Luis have made the Blues much stronger this season.

After a term without any silverware, manager Jose Mourinho signed Costa, Fabregas and Luis for £75m, as well Didier Drogba and Loic Remy, while goalkeeper Thibaut Courtois returned to west London after three successive seasons on loan at Atletico Madrid.

Spanish duo Costa and Fabregas have played a crucial role in the club's impressive unbeaten start to the Blues campaign, while, with Cesar Azpilicueta excelling in the left-back, Luis is yet to have made the same impact.

"Last season, the team was very good but this year we are a bit better. Cesc has come, Diego and also Filipe," Oscar said to Chelsea's official website.

'We've been playing so well, everybody has been playing so well. We have such a strong team and in every game we try to be compact in order to win the match. We need to control the games.

"The manager wants us to stay confident but not too much because that can be dangerous. He tells the attacking players to score goals and enjoy our football but when we don't have the ball we have to defend as a team."

After a goalless draw against Sunderland, Chelsea secured a comfortable 3-0 win over Tottenham Hotspur on Wednesday 3 December to maintain a six-point advantage over second place Manchester City.

Oscar said: "We keep our feet on the floor because we haven't won the league, we haven't won the Champions League, it's just the start of the season. We have so many games still to play and we need to win them."

Meanwhile, the Brazilian has also hailed the summer arrival of veteran Drogba after the 36-year-old proved he still has what it takes to replace Costa up front by scoring against Spurs.

He said: "Didier is a fantastic player and a fantastic person. I'm so happy he's part of the squad. He speaks to the attacking players before the game and he still wants to score goals.

"I watched him on TV when I was younger and now we play together. He's scored so many goals for the club and he pushes all the young players to be the best."