The Barclays Premier League leaders' place in the last 16 was already confirmed prior to their 3-1 defeat of Sporting Lisbon on Wednesday night.
The Blues could play Juventus, Basle, Bayer Leverkusen, Paris St Germain or Shakhtar Donestsk in February's first knockout round.
"I don't think any of the big teams is out of the Champions League now
Maybe Liverpool," Mourinho said.
"But all the teams that want to win the competition, they're all in the competition.
"Season after season you repeat this; normally everyone is in the last 16.
"Everybody's there, so the Champions League starts now.
"What can we do? I don't know
Last season, for sure, we were not one of the top four and we played in the Champions League semi-finals.
"Let's see what we can do this season, step by step."
Chelsea will discover their opponents in Monday's draw.
Immediately after the match Mourinho told Sky Sports: "There are a few sharks in the ocean."
Asked if he likes swimming with sharks, Mourinho said: "Yes, I like
In a cage
I did it in French Polynesia
I didn't want to go, but my wife and my kids, they pushed me."
He has no preference for the last 16, but would not underestimate any opponent.
"The draw is the draw," Mourinho said
"We have five possible opponents.
"I'm happy (Manchester) City and Arsenal went through
I'm not happy they finished second because they blocked two other possible opponents.
"Paris would be good, because it's easy to travel for us, for the fans
It would be good, but we can't decide the draw.
"The hardest? Everyone is hard
You think Basle is easy? We lost twice against them last year
They beat Liverpool and three years ago they beat Manchester United.
"Leverkusen, Shakhtar..
I don't think there are any easy teams at that moment."
Asked why he was pleased two other English teams had advanced, Mourinho explained it would benefit Chelsea's Premier League push.
He added: "I work in England
I want the prestige of English football and I hope they do well.
"And we have also Liverpool, Tottenham and Everton in the Europa League, so I wish them good (luck) too.
"At the same time it's good for us that our direct opponents in the Premier League are involved in European competitions.
"Manchester United are not
They have the same advantage that Liverpool had last season in terms of the Premier League, a big advantage."
Mourinho was also happy with the performance as Chelsea responded from a first loss of the season - a 2-1 defeat at Newcastle in their 24th game - with victory.
A Cesc Fabregas penalty and goals from Andre Schurrle and John Obi Mikel - his fifth goal in more than 300 Blues appearances - earned the win.
Mourinho said: "We did what we had to do
We played seriously and we deserved to win, I believe
Good attitude
The players were serious."
Diego Costa played the full 90 minutes after Mourinho suggested he needed to work on his sharpness following the Newcastle loss.
Mourinho thought Costa's performance was "very good", adding: "He wants to improve his condition.
"The confidence is not high, his condition is not the best
(But) he always wanted the ball, always wanted to associate with the wingers and with Fabregas.
"Very important for him
Better than against Newcastle, better than against Sunderland."
Ruben Loftus-Cheek, the 18-year-old midfielder who has been at Chelsea since the age of eight, made his debut.
Mourinho's instructions prior to introducing the teenager were simple.
The Blues boss said: "'I give you this, you have to give me a nice bottle of red wine'
He told me, 'no problem'."
Sporting needed only a draw to advance, but the loss left them relying on Maribor avoiding defeat against Schalke.
But the Germans won 1-0 in Slovenia to advance to the knockout stages.
Sporting boss Marco Silva said: "Unfortunately we couldn't get the point we needed here.
"We're not happy with the defeat
We were expecting more, but we have to carry on.
"All our aspirations were killed when they scored that third goal."
Source : PA
Source: PA