There are two different Lineup Leaderboards - Current Year Only and All Years. In order to be eligible for the Current Year Only Leaderboard - your Lineup may only contain players from the current Game Year (MUT 16). If you have any previous year players (MUT 15) in your Lineup, then you are only eligible for the All Years Lineup.
If you believe you should be on the All Years Leaderboard but are not seeing your account listed, check your Lineup carefully to make sure that there are no MUT 15 cards.
The Leaderboards only pull a certain number of players to be listed. Sometimes, the Leaderboard will cut off the list even though there are more people that have the same Overall Rating. So if you are a 95 OVR, and the Leaderboard ends with 95 OVR players, it's possible that the Leaderboard filled up before it got to your account.
The leaderboards no longer calculate in real-time. Some of the Leaderboard may be delayed up to 2 hours - this is to prevent Leaderboard re-calculations from slowing down the pack opening experience for our users. So if you believe that you should be on the Leaderboard , you may have to wait up to 2 hours before your account may appear.