A healthy win over Scotland could be more beneficial than Sri Lanka think, ahead of their Cricket World Cup clash in Hobart on Wednesday.

The already-qualified Sri Lankans finish their Pool A campaign against the winless Scots, and while victory is expected against their associate opponents, a large margin could ensure they avoid a quarter-final with India.

With MS Dhoni's men on track to top Pool B, the fourth-placed side in Pool A will go head-to-head with the World Cup holders in the knockout stages.

Bangladesh (seven points) occupy third spot ahead of Sri Lanka (six), and finish the group stage against unbeaten New Zealand - but rain is expected for their clash in Hamilton on Friday.

A washout - it would Bangladesh's second of the tournament - would take the Tigers to eight points, a target Sri Lanka can reach if they beat the Scots.

With no way of knowing what Bangladesh will finish on, Sri Lanka may just require a big win to overturn their net run-rate deficit on their sub-continental rivals - Bangladesh are 0.362 ahead.

Regardless of the identity of their quarter-final opponents, Sri Lanka rest easy knowing their final-eight clash will be in Sydney on March 18.

Coach Marvan Atapattu could see Rangana Herath return for the knockout fixture, but replacement off-spinner Tharindu Kaushal might get a chance against the Scots.

Atapattu offered some kind words for strike bowler Lasith Malinga, who was criticised earlier in the tournament for his output and fitness.

Since going wicket-less in Sri Lanka's tournament-opening loss to New Zealand, Malinga has got figures of 3-41 (Afghanistan), 3-35 (Bangladesh), 1-63 (England) and 2-59 (Australia).

"He's been brilliant, in the last game especially," Atapattu said, referring to their loss to Australia in Sydney on Sunday. 

"There are big-game players, Lasith is one of those. 

"He stands up when there's a big game, pressure situation ... he is a great asset to the team and bowling unit."

And if Sri Lanka's only previous one-dayer against Scotland is anything to go by, both a large win and a Malinga bag of wickets are on the cards.

The two nations met in July 2011, with Malinga snaring 5-30 as Sri Lanka won by 183 runs in Edinburgh.