Kevin Pietersen has described Tymal Mills' £1.4million Indian Premier League deal as a slap in the face for Test cricket.
Former England batsman Pietersen voiced his concern on Twitter that a Twenty20 specialist has become one of the current national team's best-paid players, and called on the International Cricket Council to arrest the decline of Test matches.
Fast bowler Mills and Ben Stokes, a match-winner in all formats for his country, scooped by far the biggest pay packets when they were signed by Royal Challengers Bangalore and Rising Pune Supergiants respectively in Monday's 2017 IPL auction.
Pietersen, who last played for his adopted country three years ago before being controversially sacked in the aftermath of England's 2013/14 Ashes whitewash defeat, has been limited to Twenty20 cricket himself since his last first-class match in June 2015.
The 36-year-old wrote: "Another SLAP in Test cricket's face yesterday! A T20 specialist becomes one of the current England team's richest players!"
At 24, Mills is able to play only the shortest format because of a congenital back problem which has forced him to retire from both first-class and 50-over cricket.
Pietersen added: "I don't blame him at all! I ❤how T20 is growing the game! I'm just saying that Tests are falling way behind atm! ICC needs to act & quick!"
In 2012, he was dropped for the Lord's Test in a dispute with his employers which reportedly emanated in part from his IPL ambitions.
Pietersen is currently in action at the Pakistan Super League but ruled himself out of the reckoning to be signed at auction for this year's IPL, so that he could take a break during April and May.
On the subject of Twenty20, he added on Tuesday: "I embraced it 8yrs ago & it's what caused me my P45! I absolutely love how all these youngsters are now benefiting!"
