Student or Learner
"The Grizzlies wouldn't mind the Spurs being cautious." (Source: Ginobili (elbow) may play in Spurs' playoff opener | NBA.com.)
I'm wondering whether there should be an apostrophe after "Spurs," since one can replace "Spurs" with a possessive.
"The Grizzlies wouldn't mind their being cautious."
In informal English I would say/write "them," but, if I'm not mistaken, in formal English only "their" would be acceptable.
There is little agreemeent on this, even among the 'experts'. I wouldn't worry about it if I were you.