Try throwing some diagonals into your easy runs to bring a bit of extra speed into your week and it will also help improve your running mechanics. You want to aim to run the diagonal between 3 - 5km pace building into it and easing off as you get near the corner of the pitch and jog the baseline to recover. It should feel comfortable and not like a full on interval session where you are gasping for air at the end. Aim to do these in the middle of your easy run when you are nice and warmed up!