Carlo Ancelotti has admitted Everton's new system is an "emergency" thanks to important players being out of the side.
Over their last two matches, Everton lined up with a three-at-the-back formation rather than the 4-3-3 which served them particularly well at the beginning of the campaign.
Everton are contending with injuries in both full-back positions to accommodate that switch.
Lucas Digne had surgery on an ankle ligament issue earlier in the week, while club captain Seamus Coleman picked up a problem while on international duty with the Republic of Ireland last month.
And Ancelotti said that it's only because of those absences that the Blues have switched their formation.
He told his pre-Burnley press conference: "I think it's an emergency because we have two important players in Coleman and Digne out. It is only for this reason.
"We have the quality in the squad to play also with three centre-backs, because we have a lot of good centre-backs.
"But I think it's a moment.
"The fact that we can play with three or four is good for us."
Coleman was pictured back at Finch Farm in the build up to this weekend's match against Burnley.
However, Ancelotti confirmed that both he and Digne would still be out of Saturday lunchtime's trip to Turf Moor.
"Apart from Coleman and Digne, all the players are available," he added.
"He [Coleman] doesn't play. He's training individually."
The manager also gave his opinion on the current discussion around five substitutes being introduced to the Premier League.
The issue was not raised in a meeting between the chief executives of clubs earlier in the week, but that didn't surprise Ancelotti.
He remarked: "I'm not surprised [it didn't come up] because there is discussion about this, who wants three and who wants five.
"I think, at the end, it's important to take care of the health and welfare of the players."
