During my run on Tuesday, there was discomfort in the left foot again but at different areas. Pain occurs at the back of the left heel upon pressure being exerted by the foot surface.
I also had some mild contusion(blue-black) on the ball of my left foot many days ago, but that felt good enough to continue running the next day. However the pain came back again, possibly because I exerted too much pressure at the ball due to the hurting heel.
Might be a small technical defect of the landing of my left foot. It's probably not gentle enough, and the problem surfaces after multiple days of running. Muscles at the (left?) foot are not strong enough yet. Probably a combination of several reasons.
So now I am down again for another 2 days and not recovered yet. Hmmm.....