COMMERCE CITY — The Colorado Rapids dropped 3-0 Arsenal F.C. on Monday. In front of a near-sellout crowd at Dick’s Sporting Good Park full of supporters for the English Premier League giant, Colorado tested their depth and youth. Due to a game two days beforehand in Portland that actually counted and a fixture against NYCFC on Saturday, the Rapids only had several regulars get minutes. Mainly, it was a 10-minute show at the end of the contest when the gunners played poster boys Alexandre Lacazette, Mesut Özil and Pierre-Emerick Aubameyang.