Torres has been out of action since being substituted in a 2-0 defeat at Newcastle United on November 2 due to an abductor muscle injury.
However, the Spain international travelled with the Chelsea squad for the Group E clash at St Jakob Park, with manager Mourinho revealing on Monday that Torres is available.
"Torres is ready to play. He trained with the team yesterday and this morning with no limitation and he is ready to play," said the Portuguese.
Chelsea have surged to the top of the group, collecting nine points from three games since their shock 2-1 defeat to Basel at Stamford Bridge on matchday one.
While Mourinho accepts the Swiss champions - who currently lie third in the pool - deserved to win that match, he has urged his side to focus on securing qualification for the knockout stages by gaining revenge on Tuesday.
"Basel are a good team. They won in London because they played better than us (but) we are in a better situation now," he added.
"If somebody tomorrow has to feel the pressure it's not us, it's Basel.
"Tomorrow we can finish the job to qualify. After the first match, we did our job."
Chelsea face a run of seven games in the next three weeks as the season enters its busiest period for English clubs, but Mourinho is relishing the challenge this fixture congestion brings.
"This is a period I like because the squad play a role. Only the brave can survive because of the accumulation of matches," he added.
