FIFA secretary-general Mattias Grafstrom has told staff at world football's governing body that "individuals, unstable moments and unfortunate episodes come and go" as pressure mounts on Gianni Infantino following the collapse of his FIFA Forward Enterprise (FFE) plan.

Grafstrom, second in rank only to Infantino at the organisation, had been silent on the crisis that has engulfed FIFA over the last week. But in a letter sent to staff on Tuesday morning, seen by The Athletic, he described the scrapped FFE plans as a "sad and reproachable series of events — which were thankfully concluded with the FFE project permanently abandoned".

The Athletic previously reported that Grafstrom was not aware of the FFE scheme, which had been drawn up by Infantino.

"The last week has been both extraordinary and challenging for all the members of FIFA staff in our offices around the world," his internal memo read. "This is why I wanted that you were the first ones to hear from me.

"We have all been thrown into the middle of a turmoil, which is difficult to comprehend and accept.

"I assure you that you as members of the administration, you will be defended and safeguarded from the political context we currently experience. You do not need to worry.

"Individuals, unstable moments and unfortunate episodes come and go. The institution, its mission and its responsibility towards world football continue, and that is why we should always keep our professionalism, sense of perspective and composure."

Although Grafstrom's comments were sent internally, he joins Kevin Lamour, FIFA's chief operating officer, in criticising the plans drawn up by Infantino. In a statement to the Associated Press last week, Lamour said staff at the organisation had been "deceived" and described FFE as "the project of one person".

Infantino's senior advisor Carlos Cordeiro also resigned last week due to his opposition to the plans.

Wenger: Withdrawal 'absolutely necessary'

Arsene Wenger, the former Arsenal manager and current chief of global football development at FIFA, revealed he first learned about Infantino's failed FFE proposal through the media and said the governing body's withdrawal from it was "absolutely necessary and beyond question".

"The recent events at FIFA deserve some clarity from my side," a statement from Wenger, shared by FIFA, read. "I was not involved in this strategic plan and first became aware of the project through media reports.

"The decision to withdraw the project was absolutely necessary and beyond question, because I firmly believe in an independent FIFA that serves our game with commitment, transparency and integrity."

UEFA calls for Infantino to go

UEFA, European football's governing body, has called for Infantino to step down, saying it has lost confidence in his leadership. In addition, the English Football Association is set to follow the Football Association of Wales and withdraw its letter of support for Infantino's re-election next year.

FIFA has been approached for comment.