Malinga had been Sri Lanka's most penetrative bowler in the group stage. Although he collected figures of 0 for 84 from the curtain-raiser against New Zealand, he has since taken 11 wickets at an average of 28.27. He was particularly impressive against Australia, as he claimed 2 for 59 from his 10 overs, even as the team conceded 376.
Malinga had had an operation on his left ankle - which bears a considerable load during his delivery stride - in September. His first competitive cricket upon return were the warm-up matches ahead of the World Cup.
"Lasith's put in a lot of effort over the last three or four weeks to get into rhythm," Jayawardene said. "You have to give him a lot of credit, having had an operation on his ankle. He hasn't bowled for four months, and it takes a lot for a guy to come back for a big tournament. The biggest thing for him was to mentally be ready to land that foot 100% knowing that there was no pain. Once he did that he's bowling really well.
"I think the Australia game and the England game before that, his finishing has been pretty good, his movement has been good, the variations have come good. When that happens the rest of the bowling unit picks themselves up around Lasith. When Lasith's a bit down, everyone else is a bit down as well, so the last few games have been good. You don't want to peak too early. You want to play your best cricket at the business end."
Jayawardene hit a match-winning hundred against Afghanistan after his team had slipped to 18 for 3, then 51 for 4 chasing 233, but has since had limited opportunities to spend time in the middle. He was not required in the matches against Bangladesh and England, in which Sri Lanka only lost one wicket each, but then got himself run out against Australia for 19, and miscued an expansive shot against Scotland, early in his innings.
"The top-order guys have been batting really well, which is a good thing for us," Jayawardene said. "But if they miss out, then obviously the onus is back on me to make sure that we control things. That's how it is. In big tournaments and big games, we've been playing some good cricket together. We just need to make sure we hold our nerve."
Sri Lanka's recent history of holding their nerve in vital games jars with South Africa's reputation for cracking under pressure, but Jayawardene said Sri Lanka could not bank on the opposition falling apart again. His team would instead aim to approach the quarter-final as just another match, he said.
"It's all about us playing good cricket and you can't play good cricket if you put yourself under pressure. It hampers your thinking processes. It's important that we play good cricket and whatever the end result, we can then talk about it afterwards. But if we start thinking about winning, winning, winning, it's going to be tough for them to go out and perform. That's how we have been playing for a long time and it's helped. There is no other secret to it. It's about guys handling that pressure much better than others.
"What we have spoken to the guys is that we are playing South Africa. They are a quality team and have got some fantastic players. We need to play assuming that they are going to bring their A game. If they fail to do that, then it is on their heads, but we can't talk about that."
Jayawardene also said Kumar Sangakkara's bumper crop of hundreds in the tournament was another manifestation of his consistency over a career. As Sangakkara approaches ODI retirement, he appears set to become the first Sri Lanka batsman to finish with an ODI average above 40.
"Apart from probably the first three years in his career, and maybe a year in between, Sanga has been very consistent. He is just enjoying himself. We know that we are not going to play cricket anymore. It's not a burden for us - it is about going out and enjoying ourselves. I don't think Sanga would have played to get four centuries in a row, but the occasions came about. I think it is due to the attitude and the commitment the guy has."
