Reducing the number of teams in the Premier League would be one way to accommodate an expanded Champions League format, according to Juventus chairman Andrea Agnelli.
The Italian also chairs the European Club Association and gave the body's approval to UEFA proposals for a new-look continental competition to begin in 2024 with 36 clubs instead of 32.
Under the proposal, teams would play 10 matches in the autumn rather than the current six in the group stage, as part of a 'Swiss system' within a 36-team league.
Last month, Sky Sports News reported UEFA's proposals for a 'Swiss-style' Champions League from 2024 onwards were not challenged by a single association during a two-hour meeting.
- Champions League reforms not challenged by any associations
- CL last 16: Will Juve, Barca complete second-leg comebacks?
UEFA hopes the new format, which guarantees clubs more games and more revenue, will avert the threat of breakaway European Super League.
Agnelli is hopeful an agreement on the new format could be reached within a fortnight.
The Premier League is understood to have concerns with the increased number of matches contained within the proposal, but Agnelli suggested 20-team leagues might look at a reduction in domestic games to overcome the problem.
"The balance we are trying to strike is one-third international [games] to two-third domestic," he said following the ECA's general assembly on Monday.
"We have countries such as England with the maximum number of games at 53 or 54, Germany is 43. So it's having a balanced competitive landscape.
"We do think that currently, for competitive balance purposes, 20 teams in leagues - it's not just the big leagues, but in many leagues - there are too many.
"And so there is an overall element that could actually be worked out altogether in the interests of everyone."
However, Premier League chief executive Richard Masters said last month reducing the number of teams is not something they are planning on doing any time soon.
A proposal made last year - called 'Project Big Picture'- was designed to change the voting structure of the Premier League and funding models for the English Football League and Football Association.
There were several other major changes to the structure of English football put forward, including a reduction from 20 to 18 teams in the Premier League and the scrapping of the EFL Cup and Community Shield.
But speaking at the Business of Football summit, Masters said: "The English football calendar is jam-packed with excellent exciting football. It's something you come to along the journey.
"At the moment and for the foreseeable future, the Premier League is a 20-club competition."
Questions remain over allocation of four extra places
Agnelli described the Swiss system - whereby teams do not play every team in the league, but teams with differing strengths based on a seeding system - as "beautiful".
He also acknowledged one of the key issues to overcome is access to the competition, and in particular how the four extra places should be allocated.
The European Leagues group - of which the Premier League is a member - is opposed to the idea of clubs qualifying via historical 'co-efficient' rankings rather than performance in the most recent domestic season.
It is holding a club advisory platform on Wednesday, with all clubs invited to attend.
Agnelli understood the argument of allowing domestic champions from a broader range of countries to have access to the new-look league.
But when asked whether a dangerous precedent was being set in allowing teams into Europe based on historic performance, he added: "Unprecedented events can turn into normality.
"Some years ago it was unprecedented that not just the champions were allowed in the Champions Cup, and then it became normality."
Champions League changes may see some £100m-plus transfers 'banned'
One feature Agnelli also revealed is under discussion is the possibility of banning £100m-plus transfers taking place between sides in the revamped Champions League.
The plan would encourage clubs to buy players elsewhere in the football pyramid and control costs as the game attempts to recover financially after the coronavirus pandemic.
Speaking solely in his role as Juventus chairman, Agnelli said: "We could think of double paths for the transfer system, whereby clubs qualifying to specific tiers in international competitions wouldn't be allowed to buy each other's players, so that would actually improve the indirect solidarity towards the other clubs.
"So, no triple-figure transfers amongst Champions League-participating clubs. Maybe we will be focussing too [on] the champion players of smaller countries, so allowing us only to buy players there, for example. These are elements that we are discussing.
"Cost-control, it's one of the elements that gave us the biggest headaches, and will be the biggest challenges, in terms of reforms going forward, where all clubs will be particularly focused on in the next set of discussions."
Among the transfers that would not be permitted under the proposed new rules, are Neymar's £197m move from Barcelona to PSG in 2017; Kylian Mbappe joining Neymar in the French capital from Monaco for £166m the following year; and Cristiano Ronaldo's switch from Real Madrid to Juventus for £105m, also in 2018.