LONDON (AP) — Seeking to keep the Davis Cup attractive to top players amid a crowded calendar, the international team event in men's tennis will test a two-day format and best-of-three set matches next year.

The changes will be applied for matches in Zonal Groups I and II — the tiers below the World Group — starting with the first round in February.

Group I matches will be played on Friday and Saturday, and Group II matches on Saturday and Sunday. The singles will be played on Day 1, followed by the doubles and then the reverse singles on Day 2.

ITF President David Haggerty said the changes could be applied to World Group matches if the trial is deemed a success.

In other trials taking place following a vote by member nations at the ITF's annual general meeting in August, team sizes can be increased from four players to a maximum of five for matches in the World Group and Zonal Groups I and II.

Also, there will be no fifth match if the fourth match is decisive. If a team takes an unassailable 3-0 lead, only the fourth match will be played.

"We are working to develop player-friendly formulas that give the competitions the profile and stature they deserve," Haggerty said in a statement released Friday.

Among other reforms approved in August, pre-match commitments for players in Davis Cup have been reduced and finalists have been given the choice of hosting their first-round matches the following year.