Valencia has kicked off the season in outstanding form after vacating the famous No7.
"I think it turned out to be a very good number for me when I first arrived at the club as I was just given the no.25 more or less," he told MUTV.
"But things went really, really well. I played well wearing that shirt so I think it was a decision I came to in the summer. Maybe if I can get back to the form I showed before, why not? It is a good idea to start wearing it again.
"It had been something I had been thinking about for quite a long time. I'd been considering a change back and maybe it is psychological or maybe it is just all about a good-luck symbol, if you like. We get a lot of that in Ecuador, maybe superstition, and l hope it continues and still brings me more good luck this season."