If the mastery of spin and the flags in the stands had not made it clear Sri Lanka are enjoying home conditions, then the teams' training schedules over the past week has laid this truth out.

As day-long northeast monsoon rains break up and recede into the sunset hours by late November, Sri Lanka have been wise to switch their training times to the morning. They had been scheduled to train under lights, but for the second time in a week a late-afternoon thunderstorm arrived at the ground at the same time as England, by which time Sri Lanka had completed their practice and departed.

It may all come to little. The forecast is not good for the next two days. But with Mahela Jayawardene unavailable for this match, vice-captain Lahiru Thirimanne said Sri Lanka's top order has the chance to prepare for another rainy day, a few months in the future.

"Mahela is a big loss. He is normally our backbone, because he strengthens up our middle order," Thirimanne said. "But this is a good challenge for our younger players as well, because we have to replace him some day. This is an opportunity for them to show what they're capable of. "

Sri Lanka have drafted Ashan Priyanjan into the squad as cover, but the team manager confirmed that he is unlikely be in the XI on Wednesday. Thilina Kandamby, 32, is likely to play his first ODI since 2011 instead. With middle order spots still up for grabs in the short term, Jayawardene's replacement will seek to earn a World Cup berth as well.

But the exact team combination, and batting spots, will also depend on the weather. A shortened game might see Sri Lanka move closer to their T20 blueprint. Thirimanne has already been moved around plenty in his relatively brief career, so he hopes for some stability in his role. "I don't think I will move up to take Mahela's spot, because I will play my normal number six position, hopefully. We'll have to see about the length of the game. According to that, I'm ready to play at any position.

"We had a good match last game, so the boys are really looking forward to this match. Confidence levels are really high. Hopefully we can play a full fifty over match tomorrow.

"I think it's a must-win game for us, because if we win tomorrow, we'll have a good chance of winning the series on the seventh."

Sri Lanka's 2014 dominance over England has in part been due to their muzzling of Alastair Cook. The England captain has 10 and 22 in the series so far, as the din for his exit from the ODI side grows louder. Thirimanne hoped his team could extend Cook's poor stretch, just as they had done in the summer, when Cook only crossed fifty once in eight innings against Sri Lanka, across all formats.

"We all know he's a very good batsman. We have to apply pressure on him, because if we do that, the whole team will be a little bit under pressure. Hopefully we can get him out early tomorrow as well. Normally every batsman goes through rough patches, but we want to concentrate on our bowling."