There were at least two seasons where Manny pulled minor work stoppages before the Trading Deadline and was rumored to have asked for a trade. I remember that he was held out of a game played on the Trading Deadline. Everyone expected that he would be traded, but 4:00 came and went and Manny PH to a nice ovation. I could be mis-remembering, but I don't think so.
In one off season the Red Sox put him on irrevocable waivers because h was not happy with Boston, but there were no takers for his long term deal at $20 million/year.