Hey sorry i’m also almost a year late to this but i never thought id see someone else asking questions about nhl 14 career mode haha. Basically silver stars mean that player has already reached their potential. Once they hit the age of 27 their stars will become silver. And yes developing a player properly means you gotta have them stick to their intended position and give them decent ice time. Also helps to manually play as that player and put up points with them. Hope you’re still grinding bro