Unfortunately, at least to my knowledge, there is no Online Career Mode for FIFA 15, nor have there been in any previous FIFA installments.
There are however a couple of Online (PvP) modes that support co-operative play. One of which is Pro Clubs, in which, you and a number of friends create a team. The players in this team comprise of AI and Virtual Pros (which is basically a player you create). In this game mode you take on other people's teams in an attempt to reach Division 1. You can also compete in cup events that happen once or twice a month.
The other game mode is Co-Op Seasons, in which you and a friend (I think this is limited to one other player only, not sure though) play as any team on the game, and you play against another co-op team playing as another team. The aim is the same as Pro Clubs, in which you try and reach Div 1, along with the optional cup windows.
In both game modes, Matchmaking is customised according to what Division your team is in; so people in Div 10 wont be put against people in Div 3 for example. And in Co-Op Seasons, Matchmaking is also calculated against the team you select's star rating; so you won't get Accrington Stanley vs Barcelona for example.
More information on Pro Clubs and Co-Op Seasons
I cried when I had to use tactical defending.
But after numerous attempts I found somethings that works for me.
-Make sure you are mostly facing your opponent and not running behind him. That means dont rush into a player let him come close to you then do the tackling.
-Along with jockey you should use team-mate contain(if you start using this feature you will get similar feel as legacy defending)
- Mostly jockey on the wings not in the middle of the park.
- In the middle of the park use the normal contain
- Always always watch out for through balls as soon as you see them coming start running back wards
After using all these techniques you will start seeing a lot of interceptions(specially by using teammate contain)
BEST OF LUCK!
Best Answer
Fifa Ultimate Team. You can read more about the 2016 version here: https://www.easports.com/fifa/ultimate-team/features
Basically you build a squad of cards for playing against people online. There are different levels of cards including bronze, silver, gold, and special Team of the Week/Team of the Year cards that give stat boosts to players. In addition to player cards, there are also manager, contract and item cards that you use to keep your team together and healthy.