Pietersen was released from his central contract in February with England and Wales Cricket Board's (ECB) managing director Paul Downton saying the decision was necessary 'to rebuild not only the team but also the team ethic' after the Ashes whitewash.
According to the BBC, the batting great expressed his sadness and disappointment at Pietersen's 'premature' exit, saying that there must have been much more in terms of what went wrong.
Richards further said he believes the ECB were looking for 'some heads to roll' and for some reason, Pietersen's 'head' was in the way, adding that judging from 'his side of the fence', Pietersen was made into a 'little scapegoat'.
The report mentioned that Jos Buttler's promotion from the one-day side into the Test side has been suggested as a way of replacing Pietersen's aggression in England's batting line-up.
Pietersen himself suggested on Twitter that Buttler could replace fellow wicketkeeper Matt Prior, who was dropped for the final two Tests of England's 5-0 series reverse against Australia after averaging 17.8 in the first three meetings, in the Test side.