What is the most important attributes for defenders, strikers...?

defenders, strikers and midfielders

Go to your tactics screen and click on each position. The key attributes for each are highlighted.

Defenders - Tackling, Marking, heading, Jumping, Positioning, Concentration, Pace(more important for full-backs)

Midfielders - can be tricky, I focus on Work Rate, Passing, Creativity, Stamina. Depends on what kind of midfielder you want. For DM he has to have good tackling and strength.

Striker - obviously Finishing, Pace, Composure, again depends on which type of striker you want as Heading, Strength can come into it too.

This is all what I look out for.

Edit - or what Andy said, had no idea about that.

Thanks man

Defenders - Tackling, Marking, heading, Jumping, Positioning, Concentration, Pace(more important for full-backs)

Midfielders - can be tricky, I focus on Work Rate, Passing, Creativity, Stamina. Depends on what kind of midfielder you want. For DM he has to have good tackling and strength.

Striker - obviously Finishing, Pace, Composure, again depends on which type of striker you want as Heading, Strength can come into it too.

This is all what I look out for.

Edit - or what Andy said, had no idea about that.

Whilst I mostly agree I would make a small change.

Acceleration is more important than pace but the two often go hand in hand anyway.

After that it depends on what type of striker but I would look for anticipation and off the ball in most of them as well.

In fact off the ball is good for midfielders as well.