Former wicketkeeper-batsman Mark Boucher believes that South Africa were "too tentative" in their batting approach during their series-deciding defeat against England in the third T20 at Cardiff on 25 June.
England clinched the three-match series by beating the Proteas by 19 runs in the final match in Cardiff.
Batting first, England posted 181/8, thanks to a 78-run innings by debutant Dawid Malan and his 105-run second wicket stand with Alex Hales.
South Africa got off to a slow start and lost wickets at regular intervals. In the end, the target proved too much for the visitors.
The series defeat comes just days after the AB de Villiers-led side performed poorly in the ICC Champions Trophy and could manage only one victory in three matches during the tournament on UK soil.
Boucher said that it was "irritating" to see how the Proteas did not come out with intent while chasing the target after they finished well in the first innings restricting England to 181.
"We finished so well with our bowling . we seem to have found a bloke (Paterson) who can hit the block-hole more often than not. It is exciting; I hope a few others take note," Sport24 quoted Boucher as saying.
"To take that (momentum) straight into the batting would have been great, but instead we batted tentatively (at first). In the first few overs chasing 180-odd you have to be proactive. We didn't go out and try to make a play, be aggressive enough," he added.
The former Proteas skipper feels that the Test squad for the four-match series against England was "a lot more mature than our white-ball teams are".
"They've come through some tough times with flying colours. But a tour of England can also get very long when you start losing games," he said.
Meanwhile, the uncapped duo of Heino Kuhn and Andile Phehlukwayo has been named in the 16-member South African squad for the four-match Test series against England, beginning July 6 at the Lord's.
The Lord's Tests will be followed by games at Trent Bridge (July 14-18), Kennington Oval (July 27-31) and Old Trafford (August 4-8).