Could Lonzo Ball be a Boston Celtic?? 

It's possible ... because Celtics co-owner Wyc Grousbeck tells TMZ Sports the team is definitely considering drafting the former UCLA stud with the #1 overall pick. 

Grousbeck was leaving the NBA Draft lottery in NYC Thursday night when he told us he's fired up about securing the top spot -- "It seems like Celtic pride is going crazy right now!" 

Wyc says the team hasn't made its mind up on who will be #1 -- but says they're looking about the 6 "really good guys" in the draft ... and bad news, LaVar -- that list includes Lonzo. 

Of couse, LaVar has made it crystal clear he wants his son in the Purple and Gold ... but Wyc says Boston ain't exactly a bad place to end up either!

"We're a place that people would wanna come and play," Grousbeck says ... "We're doing well and room for improvement."

Bonus -- Wyc says he'll have a very special VIP in the owner's box with him Wednesday night ... a huge Boston fan who's pretty tight with Conor McGregor.