"He'll sign the contract on Sunday... same as me. He is very enthusiastic about playing for the team. He already likes it here," Butler told the Malaysian Star.
Combative midfielder Boateng, 37, has played the majority of his career in England with Aston Villa, Middlesbrough and most recently with Nottingham Forest, where he had a short spell with the Championship club last season.
It also marks a quick return to work for the much-travelled Butler, who finally left MSL club Terengganu on Wednesday after weeks of acrimony where he challenged the team's decision to ban and sack him after he angered the board by discussing team discipline with the media.
MSL clubs must register their squads by mid-December and the time frame makes a deal for former Portugal forward Luis Boa Morte to join Butler and Boateng at T-Team next season unlikely.
"Boa Morte is currently under contract with Chesterfield until December, so that makes it hard for us to sign him. But we have a back-up plan," said Butler, the former West Ham player who has coached throughout Southeast Asia.
"I'm confident that the T-Team will be a strong side. Things are shaping up fine."
Johor FA have led the way with high profile signings this off season with the capture of former Spain striker Daniel Guiza from La Liga outfit Getafe that has led them to be dubbed the "Manchester City of Malaysia" by local media.
They made their second foreign signing on Friday after agreeing a one-year deal for former Italy U21 international Simone Del Nero with the option of a second season.
"The M-League has the potential to become one of the best in Asia but it needs quality players to reach the next level and I want to be a part of it," the 31-year-old midfielder former Lazio player said.