NCAA player after they either declare their intentions to leave early from school or graduate are free and clear UFAs after the August 15th signing deadline of that calendar year. They can have their rights retained until their "Senior Year" and graduation so it's not a set age from what I've seen with 20-year old Freshmen.
CHL players have two years before they either re-enter the draft if they're younger than 22, or else they become UFAs.
European players for the most part have their draft rights retained until the age of 22. From 23 to 27 they can sign with a team for a 1-year two-way entry-level contract or wait until they're 28 to sign as a UFA for any price.
22 is something of a magic number, or general rule of thumb, that applies to drafted players in terms of what age you keep their rights until they re-enter the draft or become free agents. Luckily Nikolai Prokhorkin is only 20 at this point in time.
This is from a blog by one of the CBA fanatics on Hockey's Future:
LinkFor the most part, a club retains a players exclusive negotiating rights until he's 22 after he's drafted if:
- He leaves Major Junior hockey before age 20 (if he hangs out for one year, the team has to give him that Bona Fide Offer, otherwise they don't.)
- He goes to college. He doesn't even have to stay there. The CBA allows for his rights to be extended a bit beyond the fourth year after his drafting, but doesn't allow for a way that a player can re-enter the draft.
- He plays in a foreign league
22 is kind of a minimum consideration. The CBA doesn't technically use the age and in some cases, exclusive rights can extend to age 23 or beyond, but when some four year rights to 18-year olds turn into three year rights for 19 year olds, it's just easier to say that the rule of thumb keeps almost all unsigned players ineligible to re-enter the draft or become draft-related free agents before they hit age 22.