ESPNcricinfo has learned that Brook's decision to pull out was conveyed by ECB officials to the BCCI last week, and then relayed to Delhi Capitals, who bought Brook for INR 6.25 crore (590,000) at the IPL mega auction last November.

There is no official line on the development yet from the IPL, but Brook tweeted* that he needed "time to recharge after the busiest period in my career to date". He is considered a frontrunner to replace Jos Buttler as England's white-ball captain following their group-stage elimination at the Champions Trophy, and, as an all-formats player with 18 months yet to run on his ECB central contract, workload management could prove to be a factor in the withdrawal. The ECB has been contacted for comment.

"I have made the very difficult decision to pull out of the upcoming IPL," Brook wrote. "I apologise unreservedly to the Delhi Capitals and their supporters.

"I love cricket. Ever since I was a young boy I have dreamt of playing for my country and I am extremely thankful to have the opportunity to play the game I love at this level.

"With the guidance of people I trust, I have taken the time to seriously consider this decision. It is a really important time for England cricket and I want to fully commit to preparing for the upcoming series. In order to do this, I need time to recharge after the busiest period in my career to date. I know not everyone will understand, and I don't expect them to, but I have to do what I believe is right, and playing for my country remains my priority and focus. I remain hugely grateful for the opportunities I have been given and the support I receive."

The decision leaves him vulnerable to a two-year ban from the IPL. The new rule was put in place ahead of the 2025 auction, and is based on feedback from all 10 franchises who expressed frustration at a history of late pullouts by overseas players.

In a note to franchises last September, the IPL said: "Any [overseas] player who registers for [an] auction and, after getting picked at the auction, makes himself unavailable before the start of the season will get banned from participating in the IPL/IPL auction for two seasons."

The only exception, the governing council said, will be for "an injury/medical condition, which will have to be confirmed by the [player's] home board".

The 2025 IPL will start from March 22 with Capitals' opening fixture coming against Lucknow Super Giants in Visakhapatnam on March 24. In addition to finding a replacement for Brook, Capitals also are yet to announce their captain.

*18.45 GMT - Story updated with Brook's tweet

Additional reporting by Andrew Miller