On the topic of Crowley for sure he's one of the best players in league 2 , having said that he's either holding out for a much improved contract or there are other offers on the table possibly from league 1 clubs.
Football to quote (Saint & Greavsie) "is a funny old game" and careers are usually short so players should look out for themselves. It's players agents that initiate a lot of these other contracts which are attractive to other clubs when no transfer fees are involved.