Complex sentence: Marco Bueno started his career in the youth system of CF Pachuca and after his participation in the Mundial sub- 17, Liverpool Football Club asked him to come try out on a 10-day trial.
Split into simpler sentences: Marco Bueno started his career in the youth system of CF Pachuca. After Bueno's participation in the Mundial sub- 17, Liverpool Football Club took him on a 10-day trial.