East London: South African one-day captain AB de Villiers believes that opener Graeme Smith will strike form sooner than later, and admitted that he still plays a huge role in the side.
Smith, who made 28 in East London, has not made a century in his last 33 ODI innings.
"Graeme is a huge factor in our team and plays a big part in almost everything," Sports24 quoted De Villiers, as saying.
He added: "He may not be scoring huge runs in every game at the moment, but he``s a match winner for us and I back him to return to form soon."
De Villiers also said that his team``s second win over Sri Lanka was a sterner test of his abilities.
De Villiers said he had to work harder for his money after their effortless victory in Paarl earlier in the week.
"It was definitely a bigger test for me this time around," said De Villiers.
"It was frustrating at times and really tough but I learned a lot from this game."
De Villiers said he had to think on his feet and select the right bowlers to contain the Sri Lankans towards the end of their innings.
Commenting on the dullness of the match, with South Africa coasting to a five-wicket win, De Villiers said the pitch in East London had required plenty of patience.
Meanwhile, selection convenor Andrew Hudson has said that in form opener Hashim Amla, who made a century in the first ODI and 55 in the second, would miss the rest of the series as his wife was due to give birth to their first child.
De Villiers, however, said there was enough depth in the country to get by without the opener in the short term.
Test opener Alviro Petersen was recalled as a replacement for Amla.
Jacques Kallis, meanwhile, was also withdrawn from the squad in order to rest, while Rory Kleinveldt returned home with an injury.
Seam bowler Vernon Philander was recalled, Cricket SA announced on Sunday morning, along with batsman Colin Ingram.