LOS ANGELES — Ninety minutes before the Rams new offense made its preseason debut against the Cowboys, its new top receiver stood in the tunnel of the Coliseum in street clothes. Sammy Watkins was reeling from news of his trade a day earlier. He’d just arrived in Los Angeles from Buffalo, whisked from the airport to the stadium. For Watkins, it was a whirlwind. For the Rams, his arrival was an adrenaline shot for a Rams passing game still in desperate need of one.The payoff would have to wait. Watkins knew little about the Rams offense and nothing about his expected role. He hadn’t met Jared Goff, the quarterback whose career he’s billed to save, or Sean McVay, the coach who plans to turn him into the No. 1 Rams have lacked since Torry Holt. He’d be forgiven, too, if he didn’t know the mustachioed man in the expensive suit, shaking his hand on the sideline, was the team’s owner, Stan Kroenke.
“I just can’t wait to get on the field and figure those guys out,” Watkins reiterated more than once.
But while the Rams’ new No. 1 wideout watched from midfield, it was another new receiver who started his preseason on an especially impressive note.
Since the Rams drafted him in the third round this past April, Cooper Kupp had already surpassed expectations. By the first day of training camp, he’d forced his way to the top of the depth chart at slot receiver, and since camp started, it was Kupp who seemed to be open, day in and day out.
As all eyes focused on Watkins on Saturday, it was Kupp again who separated himself from the pack in a 13-10 preseason victory over the Cowboys.
Sometimes, the separation was literal. After the Rams recovered a muffed punt early in the first quarter, Goff rolled out on a playaction boot and found Kupp wide open in the middle of the field for a 19-yard gain. Two plays later, as Robert Woods fumbled near the goal line, it was Kupp who slipped between two Cowboys and dove for the loose ball, scoring his first-ever NFL…