Both Van Poortvliet and Steward, known to Borthwick from his time at Leicester Tigers, were regular starters last year.
However, scrum-half Van Poortvliet suffered a tournament-ending injury before a ball was kicked at the World Cup, while Furbank took over the number 15 jersey from Steward during this year’s Six Nations.
“Jack is a player that was playing a lot of games for England prior to the World Cup in 2023 and then had that nasty injury,” Borthwick told BBC Radio 5 Live.
“He has worked exceptionally hard to come back from that.
“He had a couple of niggles last season and probably wasn’t quite at 100% but from what I have seen in training the last couple of weeks, the speed of ball Jack brings to the attacking game is exceptional and he is right up to his very best.”
England have shown signs of progress in their attacking intent and have led late on in each of their past four defeats.
Borthwick’s plan of kicking for both the posts and territory in a controlled performance nearly paid dividends against the Boks at the World Cup before a late Handre Pollard penalty denied them a spot in back-to-back finals.
The inclusion of Steward – a reassuring presence in the backfield and under the high ball – suggests England could be planning to kick for the skies to stifle their visitors and play for territory.
Borthwick added: “It is the right time to bring Freddie in for this game. He has trained really well and played really well for his club so far this season. George is available and I’m pleased with what he has done in the last couple of weeks but I felt it was a physical game for him last week.
“South Africa kick more contestable kicks than anybody else in the world. It means you have to be very good under the high ball and have to be good in chasing the high ball.”
Van Poortvliet, meanwhile, is a strong box-kicker and will try to manoeuvre England into better areas on the field as well as spotting opportunities to throw the ball wide for Marcus Smith to threaten the gainline.
The home crowd has yearned for more attacking rugby in recent weeks and, although England have gone some way towards delivering that, perhaps the best opportunity to get over the line against the world champions is to revert to type and play a controlled game.
