The Vitality Blast T20 tournament will begin on June 9 and conclude on September 18.
Buttler, who has only played three T20 Blast matches in the past three seasons, will be eligible for six games this season.
On June 9 and 10, Jos Butter will kick up his Vitality T20 Blast 2021 campaign with a pair of home matches against Derbyshire Falcons and Leicestershire Foxes at Old Trafford in Manchester.
Until June 20, he will go to Worcestershire Rapids, Derbyshire Falcons, Durham, and Birmingham Bears to play four away games.
Buttler, who was a member of the 2015 winning squad, is eager to make an impression and possibly play a key role in his side’s return to the finals.
“I’m incredibly excited to put on the Red Rose of Lancashire once more. It’s been a while, but everytime I return to Emirates Old Trafford to play for Lancashire or England, I’m always greeted with a warm welcome. Jos Buttler stated, “I hope I can assist the guys get off to a solid start in the Blast and create the foundations for another another run to Finals Day.”
”Having Jos available for our first six T20 matches this summer is fantastic news for Glen and the team. Unfortunately, owing to hectic international engagements, we have not seen as much of Jos in recent years as we would like, but I am confident that his availability for the Blast this summer will delight Members and fans alike. “The expertise that a Cricket World Cup champion like Jos can impart on to some of our younger players in the group will be invaluable,” Allot said, adding that it will bolster an already formidable batting line-up.