Law's men, the reigning World Twenty20 champions, head into the fourth ODI against England at The Oval on Wednesday already 2-0 down in a five-match series, with one no-result.
They've now lost 14 of their last 15 completed ODIs against England, with defeat in the series opener at Old Trafford ending their hopes of automatic qualification for the 2019 World Cup in Britain.
Instead the 1975 and 1979 World Cup-winners must now come through a qualifying event early next year if they are to secure their place in the 50-over showpiece tournament, having missed out on this season's Champions Trophy event by not being among the top eight ODI sides in the International Cricket Council rankings.
"We're not quite playing at the tempo that I think that suits one-day cricket," Law told reporters at The Oval on Tuesday.
"We are caught between Test cricket and T20 cricket -- of course we're very good at T20 cricket and we're ever-improving in the Test match arena," added Law, whose side recorded a shock win over England in the second Test at Headingley last month before losing a three-match series 2-1.
"This is the arena we need to make sure we start grabbing hold of and we start understanding, particularly with what we've got coming up early next year."
West Indies suffered a heavy 124-run defeat, with nearly 11 overs to spare, in the fourth ODI at Bristol on Sunday.
Yet they were in the contest early on, with paceman Miguel Cummins taking three wickets, including the prize scalp of Joe Root, before Moeen Ali's 102, which featured eight sixes, powered England to 369 for nine.
Veteran West Indies opener Chris Gayle, long renowned as one of the most destructive batsmen in white-ball cricket, then showed he'd lost none of his six-hitting ability by carrying the boundary six times in an innings of 94 before the Jamaica left-hander, who turned 38 last week, was run out.
"There are some good signs," said Law, who played 54 ODIs for Australia.
"Even though Moeen Ali had a day out the other day, I thought Miguel Cummins bowled very well, taking three wickets.
"With the bat, we've seen glimpses of what Shai Hope can do in white-ball cricket, Chris Gayle obviously has a fantastic record and is an imposing character on the cricket field.
"We just need a little bit more from the rest of our top order and a little bit smarter batting through that middle period."
Cummins missed training on Tuesday with a virus that Law said had been going through the squad since Headingley, although he stressed it was just a "precautionary" move.
But England all-rounder Ben Stokes, who made 73 on Sunday, will definitely miss Wednesday's match after he was arrested on suspicion of causing actual bodily harm in Bristol in the early hours of Monday morning before being released under investigation, without charge.
England have also dropped opening batsman Alex Hales, who was with Stokes on Sunday night.
Law, however, insisted: "It doesn't really matter which personnel they put out there, we know it's going to be a tough fight.
"Regardless of who puts a shirt on and plays in the opposition, we know we have got to play a lot better than we have done."
First Published: September 27, 2017, 9:43 AM IST