By Amlan Chakraborty

NEW DELHI, Dec 31 (Reuters) - England will be "cautiously" backing a proposal to make four-day tests mandatory from 2023 under the World Test Championship, joining a growing push to shorten the game's longest format.

The International Cricket Council (ICC) cricket committee is set to discuss the issue next year as the game looks for ways to free up a crammed international calendar and reduce player workload.

"We believe it could provide a sustainable solution to the complex scheduling needs and player workloads we face as a global sport," an England and Wales Cricket Board (ECB) spokesperson told London's Daily Telegraph newspaper website

"We're definite proponents of the four-day test concept, but cautiously so, as we understand it's an emotive topic for players, fans and others who have concerns about challenging the heritage of test cricket."

The ECB did not immediately reply to a Reuters e-mail seeking further elaboration.

Ashes rivals Australia already seem to be taking the same view.

Cricket Australia chief executive Kevin Roberts said last week that the board would "seriously consider" playing four-day tests.

The other "Big Three" member of the ICC, the powerful Indian board, has yet to declare its stance on the matter, with its president Sourav Ganguly saying he wants to see the proposal before commenting.

Four-day matches were given the green light by the ICC in 2017, when South Africa hosted one against Zimbabwe, while England played one against Ireland in July this year.

With an increasing number of test matches ending prematurely, the administrators are keen to free up more space in the schedules for footballncrickethub.blogspot.com lucrative shorter form matches.

Australia batsman Travis Head believes test cricket should not be denied the possibility of late drama on a fifth-day wicket.

"I think that (five-day tests) plays a lot with the wicket, brings spin into play," Head told reporters in Sydney on Tuesday.

"So I'd like to keep it at five days," he added, echoing skipper Tim Paine's view that test cricket should remain a five-day affair.

The Federation of International Cricketers Associations (FICA) fears the new gaps in calendar could well be filled with more cricket.

"It would take pressure off the schedule but our concern would be that the ad hoc way the schedule currently works they would simply plug in more cricket into the gaps," FICA chief Tony Irish told ESPNcricinfo.

While four-day tests allow a golf-like Thursday-to-Sunday scheduling, they require a minimum of 98 overs a day to be played, a challenge considering five-day matches already often fall short of their daily quota of 90 overs.

(Reporting by Amlan Chakraborty; Additional reporting by Simon Jennings in Bengaluru; Editing by Peter Rutherford and Hugh Lawson)