Torres, 28, who scored his first Premier League goal since September in Saturday's 4-2 triumph at Aston Villa, has netted three times in the last four starts and is set to continue at the expense of the injured Didier Drogba.
The Spain striker's renewed sharpness has helped boost Chelsea's team spirit in recent weeks as he has provided a series of key assists including one for Salomon Kalou in the 1-0 quarter-final first leg victory at Benfica last week.
"Strikers feed off goals but apart from that Fernando's been playing very well, even without the goals, by assisting on other goals," interim manager Roberto Di Matteo told reporters.
"He works so hard for the team. He's enjoying himself. He's enjoying playing. He's got a smile on his face and he's confident."
Ivorian Drogba, 34, who picked up a toe injury in training on Friday, is fighting to prove his fitness for Wednesday's game, as is Brazil centre half David Luiz.
Former Benfica player Luiz limped off at Villa Park with an ankle ligament injury and is likely to be replaced by England international Gary Cahill.
Chelsea have lost just once in eight matches since Italian Di Matteo replaced the sacked Andre Villas-Boas last month.
The Londoners have won six of those games to rekindle ambitions in the Champions League, the FA Cup - they face Tottenham Hotspur in the semi-finals of that competition later this month - and the Premier League where they occupy fifth place.
Chelsea will attempt to extend a 100 percent home record of four wins in the Champions League this season against Jorge Jesus's team who knocked Braga off the top of the Portuguese league at the weekend.
Benfica are now second behind Porto.
UNITED DRAW
Twice European Cup winners Benfica demonstrated their potential for an upset when they drew 2-2 at Manchester United in the group stages in November.
Coveted Argentine winger Nicolas Gaitan will be out to repeat his outstanding performance in the 2-1 win over Braga on Saturday and further impress the scouts from Europe's biggest clubs.
Compatriot Pablo Aimar, suspended against Braga, is also available to return with his vision and pinpoint passing skills.
Jesus said Benfica's first-leg defeat should galvanise his side at Stamford Bridge.
"I think Benfica were the better team in the first leg - even much of the English press recognised Chelsea were lucky to go away with the win," said the coach.
"The Champions League is really making us sweat. We still keep playing with great intensity but the fact is we don't have a lot of time to recover and we can already notice some fatigue."
Jesus's main concerns are in central defence where Ezequiel Garay, Jardel and Miguel Vitor are all out injured.
"Luisao is the only centre-back we have. That is a difficulty and we will have to be a bit creative," he said.
