In-form England will look to maintain their one-day momentum ahead of next year's World Cup when they take on a Sri Lanka side in disarray in the first of a five-match series at Dambulla on Wednesday.
But Sri Lanka are expected to prove much tougher opposition when a three-Test series begins next month, England's first for 12 years without their retired opening rock Alastair Cook.
The world's number one ranked 50-over side, England are favourites despite a historically poor record on the island.
England beat India 2-1 in July to record their eighth consecutive bilateral ODI series win with just a loss in a one-off match against Scotland tarnishing their record over the past 18 months.
Against Australia at Trent Bridge in June, they notched up a 50-over world record score of 481 as Alex Hales blasted 147 and Jonny Bairstow 139.
"We still have a long way to go," England's ODI captain Eoin Morgan said, with the World Cup just eight months away.
"It's taken us three and a half years to get to where we are, but I think we're getting to the most important part of what we've been planning towards."
The hosts are still reeling from the axing of captain Angelo Mathews after a dismal run of 30 losses in their last 40 ODIs including defeats to Bangladesh and Afghanistan in last month's Asia Cup.
Sri Lanka's new captain Dinesh Chandimal missed the Asia Cup and the preceding ODI series against South Africa due to injury and suspension but struck 77 in a practice match against England in Colombo on Friday.
"We have been trying to figure out where we have got things wrong," Chandimal said. "We have an idea now. We will let players adjust to the situations."
The three Tests, starting in Galle on November 6, will likely be a severe Test for an England side captained by Joe Root who have been all-conquering at home but fragile abroad in the past few years.
Sri Lanka crushed the visiting South Africans 2-0 in July, and have been consistent over the past 18 months, winning away Test series against both Pakistan and Bangladesh.
- Herath's goodbye -
The three-match series will end with a farewell to spin legend Rangana Herath, 40 -- the most successful left-arm bowler in Test history with 430 wickets -- who will retire after the final match in Colombo.
England's top order had a poor home series against India with uncapped Surrey captain Rory Burns having the daunting taks of replacing all-time leading England run-scorer Cook as Keaton Jennings' opening partner.
Top-order batsman Joe Denly, who provides a useful leg-spin option was also named in the 16-man squad along with Warwickshire paceman Olly Stone.
James Anderson and Stuart Broad spearhead the Test attack with Sri Lanka great Kumar Sangakkara predicting England will be no push-over.
"It's going to be a tough series for Sri Lanka against an England side who I think will be well adapted to any conditions we play them under," former prolific batsman Sangakkara said.
"I think they are the best all-round side in world cricket without a doubt, in any conditions."
The ODIs will be played in Dambulla, Pallekele and Colombo's Khettarama Stadium and the Tests at Galle, Pallekele and Colombo's Sinhalese Sports Club.
Monsoon rains appear may affect the series -- England's final warm-up match on Saturday in Colombo was washed out.
Sri Lanka ODI squad: Dinesh Chandimal (captain), Upul Tharanga, Sadeera Samarawickrama, Niroshan Dickwella, Dhananjaya de Silva, Kusal Perera, Dasun Shanaka, Thisara Perera, Akila Dananjaya, Dushmantha Chameera, Lasith Malinga, Amila Aponso, Lakshan Sandakan, Nuwan Pradeep, Kasun Rajitha
England ODI squad: Eoin Morgan (captain), Moeen Ali, Jonny Bairstow, Jos Buttler, Sam Curran, Tom Curran, Liam Dawson, Alex Hales, Liam Plunkett, Adil Rashid, Joe Root, Jason Roy, Ben Stokes, Olly Stone, Chris Woakes, Mark Wood
