It is thought that Penberthy will primarily work as a shooting coach for the side, which could help to improve the accuracy of Ricky Rubio, but coach Flip Saunders has also suggested the new staff member will add to all areas of the team.
"I don't even want to pigeon-hole him as a shooting coach because i think there are other things he'll be able to help us with," said Saunders, according to The Star Tribune.
"That will be his main emphasis. Ricky enjoyed working with him, even though it was only for a week. I think if Ricky had a chance to spend a month with him or six weeks, I believe we could have seen some good changes.
"We'll let his role evolve. It's important for him to see how we want to play and where guys are going to get shots and how he can incorporate that into our shooting."
The new NBA season gets underway on October 28.