Sri Lanka captain Angelo Mathews hopes a win over Afghanistan can see his team gather some momentum at the Cricket World Cup.

Mathews' team opened their campaign with a 98-run loss to New Zealand in Pool A on February 14.

Having had to wait eight days for their second outing, the meeting with Afghanistan in Dunedin marks the start of a busy patch.

Sri Lanka will play three games in eight days, including clashes against Bangladesh and England.

Mathews said it was an opportunity to start building their campaign.

"Hopefully we can gather momentum. The momentum is very important when you play quick turnaround games," he said on Saturday.

"Hopefully we can do the right things and keep that momentum right throughout."

Mathews said his team would avoid making too many changes, but they were yet to decide on their XI.

He expects the University Oval pitch to be a good one, with less grass than usual.

Mathews is eager to keep Sri Lanka focused and avoiding complacency, labelling minnows Afghanistan a tricky outfit.

"They're a very dangerous team," he said.

"You can't take them lightly because they can upset a team. They've got nothing to lose, they'll just come out here and try and be positive and aggressive and we expect that.

"We have to expect a good challenge, we can't just run through them. We have to fight very hard from ball one to ball 300 probably."

Lahiru Thirimanne was Sri Lanka's best batsman in their loss to New Zealand, with the opener making 65.

They will expect more from paceman Lasith Malinga, who finished with figures of 0-84 in that loss.

Afghanistan showed glimpses before suffering a 105-run loss to Bangladesh, but this shapes as an even bigger test.