Why can't you say "ayer he visto a Marcos"?
You can only use the perfect tense, "haber + perfect participle" when something is either very recent or is still ongoing. "Ayer", yesterday, is definitely not still going on, and it's not recent enough to justify the perfect tense. When something is final and completed, like yesterday is (!) we have to use the simple past - so, "ayer ví a Marcos".
CS
Related Spanish GCSE answers
All answers ▸When should I use the subjunctive?
You are writing an email to your friend Maria in Spain. She asked you about your hometown. Describe your hometown and its key features.
What is the difference between the preterite and the imperfect tense in Spanish?
Please conjugate the verb Comer