Tottenham face Everton at White Hart Lane on Wednesday knowing a victory will put them level with second-placed Manchester United and three points behind Premier League leaders Manchester City.
Redknapp is likely to recall the likes of Rafael van der Vaart, Luka Modric and Gareth Bale after resting them for Saturday's 3-0 FA Cup win over Cheltenham.
That could mean a return to the bench for Pienaar, who has started just five league games for Spurs and been linked with a return to Everton on loan, but Redknapp has told the 29-year-old that he can still force his way into his first-team plans.
"Players like Pienaar and (Niko) Kranjcar are good players and they can get in the team," Redknapp said. "You saw on Saturday that they have quality and they have a big part to play between now and the end of the season.
"Pienaar is a good lad and he is in the running to play on Wednesday now that he has got a game under his belt."
The South Africa midfielder suffered a concussion after clashing heads with team-mate Bongani Khumalo in February and picked up a niggling groin problem towards the end of last season.
He was confident the problem had gone away, but it flared up again in pre-season and he had to undergo surgery as a result, ruling him out until mid-September before another two setbacks kept him sidelined until November.
"With Pienaar the problem has been his injuries," Redknapp said. "He has never really got up and running. He seems to have injury after injury.
"He was one of their main players at Everton and it has been a difficult year for him."
While Pienaar has kept his counsel over whether he wants to leave Spurs this month, a number of players have made it clear that they want to depart.
Heading that list is Russia striker Roman Pavlyuchenko, who is attracting interest from his homeland.
The 30-year-old scored Tottenham's second on Saturday to take his tally for the season to four goals in seven starts, but is well down the pecking order following the arrival of Emmanuel Adebayor and the good form of Van der Vaart and Jermain Defoe.
Redknapp has been strongly linked with a bid to replace Pavlyuchenko with Newcastle striker Demba Ba, but the Spurs boss will only sanction the Russian's departure if he has a deal in place to sign a replacement.
"He probably wants to leave, but we can't sell him unless we can find someone who we think could make the difference to us," Redknapp added.
"It's no good getting rid of Pav if you can't replace him. You'd leave yourself with two strikers - Adebayor and Defoe - so we can't do that.
"Pav has quality and he can play. If he is at it, where do you find a better striker? You don't. He is up there with the best.
"He can shoot and score goals. If his mind is on the job you wont find too many better than Pav."
Tottenham have a number of injury problems ahead of Wednesday's game, mainly in defence.
Ledley King is out for several weeks with a hamstring tear and William Gallas has a calf injury, meaning Younes Kaboul is likely to partner Michael Dawson - who himself has only just come back from a four-month Achilles injury - at centre-half.
