While playing a sport on a soil pitch i dived and my finger got abraised ..but kept playing .. my question is after one week i got a tetnus shot . wh?

Unclear question: It is good that you got a tetanus shot, however your question, if any did not come through. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex.

Tetanus : Is 30% fatal even with modern medical care. So if your healthcare provider was concerned you were at risk due to a dirty wound and perhaps years since you had a shot this would be why they administered it. If finger red/feeling unwell/painful please get rechecked urgently for infection