Taylor Swift Is Ace in the Hole for Justin Baldoni's Lawyer in Blake Lively Case

Justin Baldoni's lawyer has an ace in the hole in his client's legal war with Blake Lively and Ryan Reynolds ... and the threat of a Taylor Swift deposition can go a long way here.

TMZ has a new podcast with Harvey Levin and Mark Geragos -- "Two Angry Men" -- and in our first episode we broke down the Blake-Baldoni beef with special guest Bryan Freedman, the attorney repping Justin.

Harvey hammers Bryan about potentially deposing Taylor ... because she's central to the dispute by virtue of her involvement in an infamous meeting between Justin, Blake and Ryan.

Taylor was there when Blake and Ryan met with Justin to discuss the rooftop scene in "It Ends With Us" ... it's the scene Blake rewrote and the meeting led to Justin's 2 AM voice note to Blake.

Bryan is cagey about calling Taylor for a deposition, but watch the clip and read between the lines ... a Taylor depo is on the table and Bryan can use it as a big bargaining chip to get a settlement.

Yes, we're already talking settlement because as Harvey and Mark explain ... there is no way this case is actually going to trial ... for the very reason that none of these celebrities want to be subjected to depositions, courtroom testimony and especially cross-examinations.

Taylor's the biggest star of them all though, and our read is that Blake and Ryan will do anything to keep their best friend from being grilled by Bryan ... which could benefit Justin in the end.