Just to compare.
Nyquist first trip up was in 11/12. He played 18 games and scored 1 goal.
Tatar first trip up was 10/11. He played 9 games and scored 1 goal.
Datsyuk's first year was 01/02. He played 70 games and had 11 goals.
Abby played 54 games over three seasons: 07-10. He scored 3 goals over that stretch.
Mantha's 2 goals in 10 games is 16 per 80 games. Those are decent numbers for a rookie that wasn't a top 5 pick.