Paul Lambert has struggled with disciplinary problems since taking over at the bet365 Stadium, with Jese Rodriguez going AWOL and never returning to the club last month while both Saido Berahino and Ibrahim Afellay have been banished from the first-team squad.
"I think the whole recruitment process needs looking at. There have been transfers that aren't even part of the squad for all kinds of reasons, whether it be discipline, whether it be lack of performance. You've got to look at that - what decisions are being made and the type of characters," Butland told reporters.
"Look at [January arrivals] Badou [Ndiaye] and Moritz Bauer - two positive signings. But you look at others and they're not even here to have an input. It's not because they were playing at the top of their game, because if they were they'd be here. Too many of the recent investments over the years are completely unused and that's unacceptable. So before anyone is signed and any changes happen, that's got to be looked at because it's been farcical really.
"I believe Paul's had an extremely difficult job. He inherited a squad where, unfortunately, there was ill-discipline and players you cannot rely on. Despite those scenarios, he's put together a really competitive side that's willing to work for him. I believe the manager is the right man for the job."
Stoke's final game of their decade-long stay in the Premier League will come away to Swansea City on Sunday.