Pep Guardiola hasn't managed a soccer game in more than seven months. Since last summer, the coach credited with Barcelona's era of beautiful dominance has preferred to bask in the anonymity of New York, far from the stress of La Liga and the European soccer rumor mill. Yet, three thousand miles away, his stock continues to skyrocket.

Part of that is down to his talent, but also the accidentally brilliant timing of his sabbatical. Due to an unprecedented set of circumstances—some coincidental, some evolutionary, and some...