Vet Justin Fields solid for Chiefs, rookie Ty Simpson sharp as Rams rally for 20-12 preseason win

Justin Fields completed all four of his passes in his first quarter as the backup to Chiefs quarterback Patrick Mahomes, then the Los Angeles Rams rallied for a 20-12 preseason victory

KANSAS CITY, Mo. -- Justin Fields completed all four of his passes in his first quarter as the backup to Chiefs quarterback Patrick Mahomes, then watched as rookie Ty Simpson led the Los Angeles Rams to a comeback 20-12 preseason win over Kansas City on Saturday.

The Chiefs signed Fields, a former first-round pick of the Bears, to serve as their veteran backup in part because they were unsure whether Mahomes would be ready for Week 1 after reconstructive knee surgery. But the two-time MVP has been ahead of schedule throughout his rehab and the Chiefs are optimistic Mahomes will be on the field to face Denver in a few weeks.

The only time Mahomes got on the field Saturday was the coin toss. He was one of the captains, even though he was never playing .

Rams backup Stetson Bennett was 4 of 6 for 38 yards in his lone quarter before giving way to Simpson, their first-round draft pick out of Alabama. He was 21 of 25 for 190 yards with a pair of TD passes to Dean Connors against fourth-stringers in the fourth quarter.

Seventh-round pick Garrett Nussmeier played most of the way for Kansas City, going 13 of 19 for 98 yards.

There were some intriguing — or at least, funny — moments in a game played almost entirely by backups.

Take the Chiefs' three-time All-Pro defensive tackle Chris Jones, who said quite pointedly earlier this week: “I don't want to play in the preseason.” Defensive coordinator Steve Spagnuolo responded by making him play a single snap: the first.

Rams coach Sean McVay had no interest in playing his starters even that much. His initial group on defense was made up not of first- or second-teamers but third-teamers trying to play their way onto the roster of a Super Bowl contender.

As for Chiefs coach Andy Reid, he at least took the game seriously enough to challenge an incompletion call. Reid won, too, when the replay showed that tight end Jared Wiley had made a spectacular toe-tapping grab along Los Angeles' sideline.

The Chiefs' home was back to its usual configuration after lower rows on the visiting side and an upper section of seats on the home side were removed for the World Cup. The stadium hosted six matches over the summer, including a quarterfinal.

The stadium also returned to its old name — Arrowhead Stadium — after it had been known as GEHA Field at Arrowhead Stadium.

Rams offensive tackle Keagen Trost, their third-round pick out of nearby Missouri, hurt his hamstring in the first quarter. He's listed as the backup to right tackle Warren McClendon Jr. on the two-deep, but started against the Chiefs.