#3 Frank de Boer (Current Team: None)
Another unattached manager, though perhaps not for long, Frank de Boer has an impressive CV. He managed Ajax for six years, winning four consecutive Eredivisie title with the Dutch giants, with whom he spent a majority of his playing career as well.
He was approached by Liverpool in 2013, but turned down their offer, stating that he was not experienced enough. When he did leave, however, he went to Inter Milan in Italy, with whom he endured a poor spell, surviving only 14 games before being sacked, but not before he signed Gabriel Barbosa, one of the most coveted talents in South American football.
De Boer has shown a tendency for helping youth thrive, the best example of which is Christian Eriksen, now playing for Tottenham Hotspur; a player whose stock has skyrocketed. The former Dutch international also recently went on record saying that he would love to manage in England, so he would be unlikely to turn down such an offer. The 46-year-old may not obtain immediate results, but he could be a fantastic long-term investment.
