Jose Mourinho is determined to move on from Chelsea's Champions League exit and focus on the Premier League title push.
The Blues, who exited the last-16 to Paris Saint-Germain on away goals on Wednesday, are five points clear of Manchester City with a game in hand.
Mourinho's men return to Premier League action on Sunday, when they host seventh-placed Southampton.
"We have 11 matches to play in the Premier League. We want to be champions, to win the Premier League, but also to be back in the Champions League, to be head of group," said Mourinho.
"We cannot promise that we win every game, we cannot promise that we win the Premier League, but we are optimistic.
"You have to be optimistic to succeed. Be optimistic. Believe in yourself."
Following the 2-2 draw at Stamford Bridge and 3-3 exit on away goals to PSG, Mourinho insisted he would take time to analyse the performance.
He declined to reveal the content of his debrief with his squad, which took place on Thursday.
"I reflect with the players not with you. I don't have to say," he added. "I had a meeting with the players, I'm working for the future and I don't have to share with you."
Mourinho refused to respond to Zlatan Ibrahimovic -- the PSG striker who was sent off in the first half as the referee was surrounded by Chelsea players -- branding the Blues "babies."
"I keep saying to you and to many of you that I don't comment on what the others say. I have my own opinion about things," Mourinho added.
"My point is that if you want to speak about Champions League you have to go to [Arsenal manager Arsene] Wenger or to [City boss Manuel] Pellegrino (sic).
"I don't want to go back. I want to go forward. I think they will cope with the pressure of playing Southampton."
Chelsea skipper John Terry defended the actions of the Blues players after the Ibrahimovic incident, and so did Mourinho.
"If they surround the referee, we are charged, we have to pay a fine. If we do that the players play the fine," the Portuguese said.
"We were charged once [this season]. We pay for that."