Off the top of my head, if a rookie is elevated at the end of the season, by means of pre-season, LTI or round 11 upgrade, then to keep them on the senior list you must forfeit your final ND pick (as in absolute final round pick, not necessarily final live pick) otherwise they go back on to the rookie list unless delisted or they walk to re-enter the draft. There is no bidding or anything. If the player is keen then no one else can touch them. Not that anyone would have gone near him even with a pole, but Petterd finished last year's season elevated so he only cost us a token last ND pick to keep on senior list.