It is not necessary to answer OP with analysis of professional teams, if someone ever played a team sport they know that cohesion depends on the best player, it is simple, maybe some games can be won as a result of that "chemistry" or cohesion that It is achieved with a season but when the difficult games come, that "individual" makes the difference.
Of course, if the best player on the team is injured, it influences my bet.
You are absolutely right, when the best player is injured, it influences the team, it is the star who gives more confidence in general, sometimes the psychic state influences a lot, cohesion or confidence in the team can be collapsed.
The psychological status of each player enters the scene, this is where the team must trust each player's talent and especially in his coach strategy.