Martinelli wasted an invitation A good throw-in from Saka provided an opportunity to score early.
Shortly thereafter, however, Arsenal managed to take the lead, and Saka scored, with the winger finishing well after an excellent Nketiah preparation.
Colorado Rapids threatened at times, but Matt Macey got on well in the net. At the other end, Nketiah shot over the crossbar after a 2-0 win by John-Jules.
Olayinka hit the top corner with a nice shot from 25 meters.
was a great way for the midfielder to sign up on the senior stage, and Olayinka is a strange case that has not always impressed on a youthful level and has been greatly appreciated by coaches at Arsenal.
Macey made an impressive stop late in the first half and Jenkinson unleashed the ball off the line as Arsenal kept the goal intact.
Emery struggled against the chance to make a change during the break.
Martinelli was impressed by his defensive work, but then showed his offensive abilities when he turned Thompson's home ball home. Shkodran Mustafi and Sead Kolasinac followed, with the latter struggling as if he were far from the pace.
Nketiah and John-Jules both wanted to get into the scoresheet, but failed to score, and Emery finally called Mesut Ozil, Pierre-Emerick Aubameyang and Alexandre Lacazette for the closing stages, with Ozil taking over the captaincy.
Lacazette and Aubameyang both tried their luck before the goal, but Arsenal failed to improve their three-goal record. Overall, this was a good first training in preparation for Arsenal, with the young players particularly benefiting from the opportunities they had.
Saka was particularly impressive in the first half, while Martinelli provided insights into his quality and performance Burton was composed in midfield.
Thompson also deserves recognition for his appearance on the left-back, but there will be tougher scores for Arsenal this summer, starting with the clash against Bayern Munich on Thursday day, with Emery set to take on a much more experienced starting lineup for this game to name.
Arsenal: Macey, Jenkinson, Chambers (62), Medley, Thompson (62), Burton, Olayinka (62), Martinelli (Ozil, 78), John Jules (Aubameyang, 78), Saka, Nketiah (Lacazette 78).