West Australian Liam Hendriks is officially a Chicago White Sox pitcher after signing a $A70 million Major League Baseball deal.

Widely considered the league's best reliever across the past two seasons, Hendriks finalised a three-year deal overnight.

Under the terms of the agreement the 31-year-old will receive $A14 million in 2021, almost $A17m in 2022 and $A18m in 2023, with the White Sox holding a multi-million dollar option for 2024.

Hendriks, who had 14 saves for the Oakland A's in the shortened 2020 season, said the White Sox had been top of his list heading into free agency as he looked to win a championship.

"At the end of the season, my wife (Kristi) and I sat down and did a list of teams," Hendriks said in a statement released by the Australian Baseball League.

"And on paper the White Sox were the team that I wanted to go to, purely based on the fact that they've got a bunch of guys I've heard nothing but good things (about) in the clubhouse, which is a big thing for me.

"They've got the best defensive catcher in baseball in Yaz (Yasmani Grandal) behind the plate, which is also huge for a pitcher."

Hendriks said the appointment of Tony La Russa as White Sox manager was also appealing, with the player feeling the 76-year-old was a good fit as an "old-school manager".

The Perth native was originally signed by Minnesota as a non-drafted free agent in February 2007.

He will become the second Australia-born player to feature for the White Sox, with Victorian pitcher Shane Lindsay making four appearances for the team in 2011.