I believe you're thinking of the Player Information page for players in multi-season and prog leagues. You click on the player's name from the Manager's Center, and then on "Regular Season Statistics," and you see his past season totals (there's also a "Playoff Statistics" link if he's been in the playoffs before).
If you're in a one-off league or an Open League, or in a multi-season league where the commish hasn't linked to the previous seasons, you won't see any past season totals.