Parking the bus is no bad strategy against a stronger opponent (althought 25 -21 is no big difference), but I would try to score from counters since 2 goals can be quickly archived with standard situations. If he plays a 4-3N-3 then I would select the 4-1-4-1, motivate wing backs, DMC, wingers, press the own half, mixed passing and activate counters. The system can be played with normal or defense mentality, I would choose normal.

I would also take a look on his bench and think about changes the opponent can do. And then check if you can react with your bench.