Andy Reid didn’t exactly peel back a layer of the mystery surrounding the Chiefs’ lineup and rotation for Sunday’s game at the Denver Broncos. Actually, when announcing earlier in the week that rookie Patrick Mahomes would get his first NFL start, Reid may have revealed more than he intended.

At least based on his experience in a similar situation. Five years ago, the Chiefs headed to San Diego locked into their playoff spot, as is the case this year.

In 2013, Reid suggested general lineup changes could occur but specified none — not even the career first start for backup quarterback Chase Daniel.

“I thought I did,” Reid said, when asked why he publicly announced Mahomes as a starter at midweek this time.

Reid’s memory of that game’s benefit, which included turning-point moments in the careers of a pair of Chiefs players, is clearer.

“I thought it was a positive, and I’ll try to give guys an opportunity this time too,” Reid said. “I have a lot of confidence in our younger guys. I think it pays off for you down the road.”

It did for current safety Ron Parker and defensive end Allen Bailey.

In 2013, Parker was in his first season with the Chiefs. He had appeared in handful of games with other teams, but his first start for KC didn’t occur until that regular-season finale.

He made the most of it. Parker intercepted Philip Rivers and recorded six tackles, and has started all but one game for the Chiefs since then.

“I was excited,” Parker said. “I remember all of the older guys on the sideline, giving me confidence to make plays. My confidence was through the roof. I played against their starters... we played lights-out.”

Parker has attempted to pay it forward this week, helping younger players prepare for what could be the biggest game of their careers on Sunday.

“Give everything you’ve got because you never know who’s watching,” Parker said. “This one game can take you a long way.”

The Chiefs are 9-6, and the outcome of their game in Denver and others around the NFL this weekend cannot change their No. 4 seed. They know they’ll open the playoffs in the AFC Wild Card round at Arrowhead Stadium next Saturday or Sunday.

It’s the ideal scenario for Reid to make some changes, but exactly what tinkering he’ll do remains to be seen. Besides Alex Smith giving way to Mahomes, the only other regular who is known to be out for Sunday’s game against the Broncos is wide receiver Tyreek Hill, who is dealing with a death in his family.

But if Sunday’s game is anything like the one that ended the 2013 regular season, many Chiefs will see the most extensive playing time of their careers. Eleven players made their first NFL start that day.

It wasn’t the first start for Bailey, but he played every snap that afternoon for the first time in his career, and when healthy has been a regular ever since.

“It was a good experience to get a lot of playing time,” Bailey said. “You go into that game really geeked up because you’re playing a lot more.”

So who might be in store for more time on Sunday? Look for wide receivers Demarcus Robinson, De’Anthony Thomas and Jehu Chesson to see plenty of action, along with running backs Charcandrick West and Akeem Hunt, although both have been battling the flu this week.

Tight ends Demetrius Harris and Orson Charles stand to get more snaps, too.

On the offensive line, Parker Ehinger, who started four games last year before a knee injury ended his rookie season, figures to see his first action this season, and Jordan Devey and Cameron Irving could see more time as well.

Defensively, players like tackle Justin Hamilton, outside linebacker Tanoh Kpassagnon, inside linebackers Ukeme Eligwe, Ramik Wilson and Terrance Smith and defensive backs Kenneth Acker, Phillip Gaines, Leon McQuay and Keith Reaser could be in line for more snaps.

No matter who plays, the objective is a 10-victory season. Bailey remembered on Friday how the opportunity to finish 2013 with a victory slipped through the Chiefs’ grasp.

They led a Chargers team that needed a victory to reach the playoffs by 10 points entering the fourth quarter but blew a chance to win in regulation when kicker Ryan Succop missed a 41-yard field goal with eight seconds remaining. The Chargers won in overtime.

“We almost won that game if it wasn’t for a missed field goal,” Bailey said. “You want to win. Period.”