There's something noticeably absent from her ring finger!

Jennifer Aniston grabbed lunch at The Tavern in Brentwood yesterday, and although the actress tried to sneak out under the radar after her meal, we caught her and noticed she's not wearing her engagement ring anymore! This could be the most solid proof yet that that she and Justin Theroux have split!

The A-list star has been engaged to The Leftovers star since August 2012, but they have been the subject of breakup rumors in recent months because they are rarely spotted together and their wedding plans seem to be on an indefinite hold. Ever since her actor beau popped the question, the Friends star has worn her bauble consistently, so it's suspicious that her sparkler has suddenly gone missing...

This week's cover story from In Touch Weekly, in fact, claims time apart and Aniston's insecurities have been driving the couple apart:

    "... now that he’s both filming and producing, their dynamic has changed. It’s not Justin’s fault — he wants to work more again. But it’s caused them to drive apart and spend much less time together. However, while they’re apart, Jen has been reportedly doubting their relationship, texting and calling him non-stop to check up. They haven’t been spending much time together at all,” a friend told the mag. “All this distance could tear them apart for good.”