Thanks for your advices.
My team badly performed during the goal drought of strikers. In last 2 matches, I selected to start 2 strikers who just played a few matches for my team but they at least showed some scoring ability. So far so good. Both of them scored two in a league match an hour ago. I will stick to use them for now. Probably they did not play many minutes per match before and so did not have good match ratings.
I know the commentaries do not show everything. However, striker had good ratings but only have 3 assists and nil goal in 18 matches is quite incredible. From my experience, some strikers do not score and will never score. But as this player had good ratings and can use both feet, I will give you more chances later.
The transfer market I faced was very difficult in early season. When I notice that there are less competitions in auctions near the half season point, I have too many transfer activities in a short period. Now it's time for finding the chemistry of players and find consistent performers.