Raiders quarterback Mike Glennon took the snap, dropped back three steps then fired a pass over the middle to what he thought was an open wide receiver in rookie Hunter Renfrow. 

Instead, Renfrow was met abruptly by Rams rookie safety Taylor Rapp, who broke up the pass on third and nine and forced Oakland to punt.

No matter where he lined up, Los Angeles' first selection in this year's NFL Draft seemed to be all over the field making plays. 

"It felt great," Rapp said after Saturday's 14-3 loss at Oakland. "It felt great to get out there and get my feet wet." 

With McVay and his staff resting the primary 25-man core of the roster, several rookies had the chance to make an impression. That led to an opportunity for Rapp, who got the start at safety alongside fifth-year defensive back Marqui Christian. Rapp had his two solo tackles and one pass breakup by halftime. 

His contributions showed up beyond his own stat line, too.

Rapp leaping into the air to challenge another Glennon throw on a separate series helped lead to cornerback Kevin Peterson record an interception in his first live game since last August because of a season-ending ACL tear sustained in the 2018 preseason opener.

"I just think the instincts and the awareness (were what jumped out at me)," Rams coach Sean McVay said Sunday. "You could just see how fast he's playing, his ability to negotiate those traffic situations."

The former Washington standout finished the game playing 30 percent of Los Angeles' defensive snaps and also saw five snaps on special teams.  

Rapp admitted he was anxious going into his first NFL game, but those feelings subsided once he made that first tackle. 

"I haven't tackled someone since last December, so I was a little nervous about the first tackle, going out there," Rapp said. "It was fun to get out there and go full go, all the way to the ground." 

A second-round pick in late April, Rapp said it was "very cool" to see the Rams utilizing his versatility – lining him up deep in coverage, at the line of scrimmage, in the box – similar to the way Washington did during his college days. 

If he continues to earn the trust of the Rams coaching staff and play like he did on Saturday, those opportunities will keep coming his way.

"He's really done a lot of nice things, but I just think you're just seeing a guy play with urgency," McVay said. "His instincts are showing up, he's playing faster, more decisive."