The game at Carrow Road is the last before Chelsea take on Queens Park Rangers in the FA Cup fourth round, which will be a rerun of the Premier League fixture that saw Terry accused of racially abusing Anton Ferdinand.
A court case is due to begin four days after the cup game and Andre Villas-Boas, the Chelsea manager, found himself being quizzed on team selection unusually early this week.
"I'll have no problem picking John - not at all," Villas-Boas said. "He'll have to compete against three others, but we'll make the right decision."
Cahill's £7million transfer from Bolton Wanderers was completed in time for the Norwich game but Villas-Boas made no promises that he would replace David Luiz, whose performances have been erratic this season.
Villas-Boas indicated that the centre-back might need more time to "adapt to the group" at a time when Branislav Ivanovic, the Serbia international, is back in training following a hamstring injury.
Fourth-place Chelsea will kick off at Norwich 11 points behind leaders Manchester City despite three successive wins, two of which have been in the Premier League at the expense of Wolverhampton Wanderers and then Sunderland.
City are at home to Tottenham, the side in third position, on Sunday while second place Manchester United travel to the side in fifth, Arsenal.
The opportunity is there for Chelsea to improve their standing but Villas-Boas wasn't paying too much attention to the weekend's top-billing fixtures.
"We need to find consistency in our own performances," he said. "It will be better if we beat Norwich but I don't care what happens in the other matches this weekend, we need to do our own job first and foremost."
Norwich, who were a League One side two seasons ago, are thriving under manager Paul Lambert and will kick off in ninth place.
Villas-Boas made it clear he had been impressed by the Scot, whose side won at West Bromwich Albion last week.
"It's a great pleasure when teams achieve something with a certain style," he said. "Victories are important for motivation, the way they play is very positive, they are fully motivated players with complete commitment to their manager and each other.
"They have had an excellent run of results, and they continue to surprise established teams in the league, which shows the value of the work Paul and his team are doing."
Chelsea beat Norwich 3-1 at Stamford Bridge in August but the game had been poised at 1-1 until goalkeeper John Ruddy was sent off conceding a penalty 10 minutes from time.
The Canaries are likely to prove stubborn opponents once more, with Steve Morison, the Wales international, their major goal threat.
Last season saw another freshly-promoted side, Blackpool, make an impressive start to the season before form fell away sharply, leading to relegation at the end of the season.
Lambert was confident that would not happen to his players however.
"That could happen to anybody but we are a different club," he said. "We're like everybody else. We need players to keep their form and hope we don't get injuries and suspensions.
"The lads are playing with a lot of confidence at the minute. I'm delighted with what they have done for me. I don't think anybody visualised this, but we are halfway through and there is a long, long way to go."