All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If the blood which pours out of the injury is very little and that it is not considered as something grave in the eyes of the people who see you, then it is permissible to perform the prayer with it. However, if there is too much blood, you should wipe it out and then perform the prayer.
Allaah knows best.