The versatile defender has added another string to his bow by lining-up in a holding midfield role so far this season.
Eric, who switched between central defensive and right-back duties last term, also opened the scoring in Saturday’s 2-2 draw against Stoke.
“First of all it’s body shape, I try to make sure I’m always side on to the play so I can always see what’s behind me,” said Eric.
“When you play right-back or centre-back, everything is in front of you, that’s easier than when you are in the middle. That’s something I’m working on.
“It’s a bit more non-stop in midfield. At centre-back, there will be times where you don’t touch the ball or the ball is away from you for a long time but in midfield, you have to concentrate for the whole time.
“There is a different demand on your body in midfield. Every position is different, you use your body in different ways and the football in different ways. It’s just about adjusting.”