The 23-year-old was banned from the squad for April's Sharjah Cup for sledging during a World Cup match against India.
Afridi was also fined half his match fee for verbally abusing Indian openers Sachin Tendulkar and Virender Sehwag, as well as umpire David Shephard.
But the fiery all-rounder insisted he was already plotting his return, courtesy of a spell in English country cricket
He said: "I will let my bat do all the talking now. I intend to use my time with Derbyshire to prove my critics wrong and win back my place in the team."
The time I spend with Derbyshire will be a learning process for me to evolve into a more responsible player
Prior to his ban, Afridi had already been in danger of being dropped from the team for a series of lacklustre performances with both bat and ball.
"I know my performances have been a big let-down for my supporters and fans," he said.
"I also accept the PCB [Pakistan Cricket Board - who banned him] decision. I think the time has come for me to change my approach to the game and be more responsible.
"And I think the time I spend with Derbyshire will be a learning process for me to evolve into a more responsible player."
Shahid Afridi profile
Afridi is among a wave of Pakistan cricketers who will ply their trade in England this summer.
Shoaib Akhtar has already been snapped up by Hampshire, Middlesex have signed Abdul Razzaq, while Surrey will be relying on the pairing of Saqlain Mushtaq and Azhar Mehmood for their championship bid.
Pakistan's national side faces a major overhaul with a new captain and coach to be announced this week for the Sharjah Cup, where they will face South Africa and Sri Lanka.
Former Test batsmen Javed Miandad is a front-runner to take over from former coach Richard Pybus, while the PCB has revealed there are three candidates for the captaincy.