Meritocracy, no matter who recommended this candidate, should be treated equally. The key is to consider whether it is suitable for this position. If you are suitable for this position and the labor cost is not high, you can sell your personal feelings by the way, but if there are problems in your work, you should tell the truth first and criticize the improvement. If no one is suitable for the position in your department, thank the person who recommended it and explain the reasons clearly. Inappropriate and mismatched things will cause unhappiness for both parties, which is also responsible for the recommended person and the recommender. I believe others will understand and agree with your consideration.