Spain midfielder Sergio Busquets warned Italy there are plenty of twists and turns ahead after Giampiero Ventura suggested moving the start of Serie A next season to help preparations for the crucial World Cup qualifier in September 2017.
Italy and Spain are locked together on 10 points at the top of Group G, having won all their matches outside of last month's 1-1 draw in Turin.
Speaking ahead of his team's friendly against Germany in Milan on Tuesday, Azzurri boss Ventura confirmed he has lobbied Serie A to shift its schedule forward from an August 20 start to fit in more games before the return clash with Spain on September 2, 2017.
"We're a bit set in our ways, but everyone else starts August 13," he said.
"It's in the national interest to play on level terms. I've already asked to play at least two more league matches.
"In a moment of madness I asked for three, but they told me to check myself into hospital."
Busquets is preparing to face England in Spain's own friendly at Wembley and sounded a note of caution at the pre-match news conference, while seeking to avoid being drawn into the debate himself.
"I don't think it's down to me to decide the fixture calendar," he said. "We know there are many games we have to pack in in all competitions.
"There are many months to pass between now and September and in the qualifying group stages there are a lot of points up for grabs as well.
"We need to go game by game and pick up as many points before the Italy game as we can."
Spain and England are rebuilding under Julen Lopetegui and Gareth Southgate respectively and Barcelona star Busquets does not believe lacklustre showings at Euro 2016 by each nation takes any of the shine off Tuesday's meeting.
"England are a top side full of good players," he added. "Like ourselves they have not done well in the World Cup and the Euros but it does not mean it isn't a great game.
"We've not played too many games with the new manager and it is an opportunity to fight and battle in a great game tomorrow night."