ALEX SMITH thought he had some indigestion. It turned out to be a lacerated spleen.

Now, the Kansas City Chiefs will put their already slim playoff hopes in the hands of career backup Chase Daniel, who will make his second-ever start tomorrow against San Diego.

The Chiefs need to beat the Chargers and hope that Baltimore loses to Cleveland and Houston gets beat by Jacksonville to reach the postseason for the second straight year. San Diego needs only to defeat its longtime AFC West rival to get back to the playoffs - and now faces a second-string quarterback.

"The guys have a lot of trust in Chase," Chiefs coach Andy Reid said shortly after yesterday's practice. "Our heart goes out to Alex. It's not something he wanted to happen. He wanted to be out there. But the guys know Chase. They're comfortable with him."

Smith thinks he was hurt on a hit early in the third quarter of last Sunday's 20-12 loss at Pittsburgh. He didn't feel any pain until after he had showered, and then it felt like cramps and pressure. He visited with the team's medical staff, but didn't go through full testing.

"Thought it was something I ate," said Smith, who ultimately took some antacids.

Smith practiced twice early in the week, feeling fine, other than some nausea. There had been a stomach virus going around the team that kept wide receiver Dwayne Bowe from practicing all of last week, so Smith and the training staff suspected that might be the cause.

The Chiefs had off for Christmas and Smith didn't want to leave his family, but a team doctor helped persuade him to undergo a scan, which, to his surprise, found a 3-centimeter laceration. There was only a bit of bleeding, though, which explained why Smith had so few symptoms.

Burkholder said scans also revealed a slight enlargement of the spleen, and Smith will have more testing to determine why that's the case. Burkholder said it might be natural.

"It's a non-surgical case. It will heal on its own, but he is going to have to have some time down from contacts and collisions," Burkholder said.

Noteworthy

* Browns rookie cornerback Justin Gilbert says he was hurt by public comments from some teammates who said he wasted this season. The No. 8 overall pick in this year's draft, Gilbert has been a major disappointment. In the past week, safety Donte Whitner and Karlos Dansby were critical of Gilbert, saying he needed to grow up as a player and person. Browns coach Mike Pettine says he has no problem with veterans giving a teammate "tough love."

Gilbert refuses to divulge his missteps but promises to work harder in the offseason, vowing "I'm going to make it right."

In another matter, the team said undrafted rookie quarterback Connor Shaw will start against the Ravens tomorrow.

Quarterback Brian Hoyer is doubtful with an injured throwing shoulder and biceps, while rookie quarterback Johnny Manziel is on injured reserve with a hamstring injury.

* The NFL fined Seattle running back Marshawn Lynch's $11,050 for "obscene gesture" after his 79-yard touchdown run against Arizona Sunday night, in which he dove backward into the end zone and grabbed his crotch.

* The Bears agreed to a 1-year contract extension with veteran center Roberto Garza. He is finishing his 14th season in the NFL and 10th with Chicago. He has made 144 starts with the Bears and 175 in his career.

* The Saints placed running back Pierre Thomas (ribs) and defensive lineman Akiem Hicks (ankle) on injured reserve, ending their season ahead of tomorrow's finale at Tampa Bay.

* Texans inside linebacker Brian Cushing was fined $16,537 for striking Ravens quarterback Joe Flacco in the head area Sunday.