VIDEO: Dale Steyn on the subcontinent wickets
Steyn was nursing a bruise while Tahir had a respiratory tract infection.
"Dale Steyn and Imran Tahir passed their respective fitness tests on Wednesday and are fit for selection for the Group B encounter," the team said in a statement.
"The team physiotherapist, Brandon Jackson, has given the green light to the players who were carrying a few niggles from the past few days," manager Mohammed Moosajee was quoted as saying in the statement.
"Dale and Imran bowled at 100% effort this afternoon and are available for selection."
Left-handed batsman JP Duminy was also nursing a stiff lower back but the team management said all 15 players were available for selection.
Coach Corrie van Zyl said the team management had not made up its mind on the bowling attack even though many expect them to rest one of the three spinners and draft in pace bowler Lonwabo Tsotsobe.
"We'll make the final decision tomorrow as to whether we should go with a totally different (attack) to the previous game," he told reporters.
South Africa will take on a Dutch outfit smarting from a demoralising defeat by West Indies but van Zyl refused to be complacent.
"We want to win the game and that's very important for us. We want to see our combinations are right going forward.
"We need to field our strongest combinations. You know this is our just second game and we are here for quite a while now so it is important we keep going."
The Netherlands captain Peter Borren said his team mates have come to terms with the defeat by the West Indies and would do their best to replicate the gritty show they put up against England in their first match.
"We were initially disappointed but the morale is fine now," Borren said.
"We don't play at this level very often. Let one full member play the other full member in four years and they will struggle too. It's not easy.
"We have to play to our standards and chase our own targets."