Answer:
a Self-fullfiling prophecy.
Explanation:
Self-fulfilling prophecies are psychological phenomena in which individuals predict an event, and due to their conscious or unconscious behavior, said event ends up happening.
For instance, Jim has a physics exam in two weeks. The exam is about thermodynamics, a topic that James dislikes because he doesn't understand it. After hearing the news that the exam was coming, he immediately claims that he was going to fail the exam. Out of resignation, he thinks: why bother studying, I'm not good at thermodynamics, and even though he may not realize it, he is setting himself up to fail. The day of the exam comes, and because he did not study one bit during the last two weeks, he loses the exam.
In this particular case, Marcus has a big wrestling match coming up, but he fears that he will lose. The week before the match, he claims that he is "really busy with other studies," and does not practice at all. Even though he may not realize he is doing this, he is setting himself up so that he will have an "excuse" in case he loses the match. Marcus is apparently engaging in a self-fullfilling prophecy.