Vasily Ponomarev (that's how his name is spelled in the NHL system) has been playing in the AHL this season after recovering from an early season injury.
He's playing for Chicago Wolves, because Carolina has no AHL team. So there has been no dedicated focus on his development. And he's still acquitted himself fairly well (29 points in 39 games).
Lucius is in college but should be able to join WBS next year, as he turns 20 in April.
Koivunen has 55 points in 57 games for Karpat at age 20. He may be a darkhorse candidate to make the NHL roster next year. Karpat, by the way, also has recent Pens draft pick Emil Pieniniemi and former Pens prospect Kasper Bjorkqvist (who has just 13 points in 44 games).