Surprisingly, yes. But also no. It largely depends on who (if anyone) finds it first and what they decide to do with it.

 

Call the number on their website for the Green Line lost & found a couple of times over the next few days - it might take some time for the train to finish its run, the item to be noticed, and make its way in to the lost & found, especially over the weekend. It might not be until the trains are given a once-over cleaning after hours unless someone turns it in.

If they don’t have it by the end of Monday though it’s as good as gone, unless someone finds it independently and somehow gets it back to you - who knows, maybe Reddit will come through.