My hunch is that your best bet would be to make a low gravity starter (1.030 or so) and pitch some of the yeast in it and use that for the next batch. The reason I think it will be fine is because I have successfully used yeast from a bottle of Saison Dupont with only 2 steps (a cup of starter in the bottle itself, and that small starter into a half growler of wort). I'm sure that yeast in the bottle was very tired at the point I woke it up and my two step process was a bad case of underpitching, but the beer itself turned out great.
In any case, by taking a chance and trying it, you'll be expanding your knowledge and can decide for yourself whether the tired yeast story has any merit. I say go for it and post your results to this thread.