Spurs surrendered their nine-match unbeaten league run in a contest that was practically over by the 18th minute following Sadio Mane's quickfire double.
"If Chelsea go 12 points clear it is a big problem, but not only for us," said the Spurs boss in quotes reported by BBC Sport.
"It is difficult to fight for the Premier League if you show that performance, that lack of desire to play for a win. If you start a game like we start then it is very difficult.
"We never coped with the tempo of their game. Liverpool deserve the credit.
"It will be difficult for anyone to catch Chelsea, it is a massive gap. More difficult than before.
"We are second in the table, my feeling now is not so good, but we need to recover after defeat and try to fight.
Before returning to Premier League action at home to Stoke City on February 26, Spurs face Gent in the last 32 of the Europa League, the two legs sandwiching a trip to Fulham in the FA Cup fifth round.