Blaine Gabbert out vs. Raiders after slicing open hand

JACKSONVILLE, Fla. -- Blaine Gabbert's rough start to the 2013 NFL season just got rougher.

The Jacksonville Jaguars quarterback, who won the starting job over Chad Henne despite suffering a hairline fracture to his right thumb during the preseason, will miss this Sunday's game at Oakland and possibly be out longer due to a laceration on the same hand.

Coach Gus Bradley made the announcement Monday, 24 hours after Gabbert was forced to leave with 1:20 remaining in the Jaguars' 28-2 loss to the Kansas City Chiefs. Gabbert completed 16 of 35 passes for only 121 yards before catching his hand in the facemask of a Chiefs defender while scrambling for a 4-yard gain. The laceration required 15 stitches to close.

"It's got to heal. And we need to keep it clean," Bradley said. "The big concern would be, with the amount of stitches, that it could re-open and then the chance of infection occurring. So we're going to handle that right."

The severity of Gabbert's latest setback caught Bradley by surprise. He said the team's doctors are worried about part of the skin having been ripped open and don't want to run the risk of sweat getting into the hand.

Gabbert, who was limited in practice last week after getting cleared to return from his thumb injury, is now on antibiotics. Bradley said he anticipates Gabbert being able to accompany the Jaguars when they leave Friday for Oakland, with a decision on whether he might be available the following week at Seattle to be made sometime early next week.

Henne took over for the Jaguars' final six plays against the Chiefs and completed three passes for 36 yards. Ricky Stanzi, who was on the inactive list, will back up Henne against the Raiders. Bradley said he and general manager Dave Caldwell plan to discuss whether to bring in a more experienced backup for as long as Gabbert is out.

"We have a guy that's seasoned and has played a lot of football for us," he said of Henne, who started the final six games of the 2012 season and the final two preseason games. "We have a lot of faith in Chad. I know he's a guy we felt strongly about going through the whole process. Hopefully we won't miss a beat."

The Jaguars' offense didn't show much life in the regular-season debut of coordinator Jedd Fisch's uptempo attack. Gabbert was sacked six times, hurried on 11 other occasions, and converted only two of the team's first 13 third-down situations. On the last of those, Gabbert's pass for running back Justin Forsett was intercepted by Chiefs linebacker Tamba Hali, who strolled 10 yards to the end zone for a touchdown that brought out the loudest round of boos all afternoon.

"Was there some rustiness? I'm sure there was," Bradley said. "Whenever you miss that many practices, there's going to be some things that aren't going to be as crisp and clean as if you practiced every day. But I thought he handled it pretty well."

Only three of Gabbert's completions covered more than 10 yards, with the longest being an 18-yarder to rookie wide receiver Ace Sanders on a third-and-23 play in the second quarter. The play originally was good for 57 yards, but the Chiefs successfully challenged that Sanders was down at the Jaguars 35.

Gabbert's quarterback rating of 48.4 ranked him 27th out of 28 starters around the league going into Monday night, with only Brandon Weeden of the Cleveland Browns being worse.

Asked what would happen if Henne played well against the Raiders, Bradley replied, "That would be a good thing." While he did not speculate about who would start whenever Gabbert returns, he came to the defense of the 10th overall pick in the first round of the 2011 draft, whose record as a starter is 5-20 and whose toughness has been questioned by fans.

"I don't know where that came from last year or in years before, but I'm not seeing it with him," Bradley said. "The guy is a competitor. He put hours and hours in this summer in the offseason, and he competed his tail off. I have no problem standing up for Blaine Gabbert and what he brings to our team.

"I understand the frustration. Sometimes when you're not successful on the field, it has a tendency to be pointed to that one person. But in this case, it's the whole team that needs to step it up."

The news on the injury front was not limited to Gabbert. Rookie cornerback Dwayne Gratz, who was drafted in the third round after not missing a game during four years in college at Connecticut, will be out at least the next three weeks after limping off late in the second quarter. The injury was originally diagnosed as a left shin contusion, and X-rays revealed what Bradley said were symptoms of a high ankle sprain.

Will Blackmon, a seven-year veteran who was signed the day before the Jaguars' last preseason game, replaced Gratz to open the second half and will likely get the start instead of seventh-round pick Demetrius McCray.

"It won't affect us too much," Bradley said of losing Gratz. "We feel strongly about Will. In the short time he's been here, he's done a nice job in there competing."

Left guard Will Rackley suffered a lateral knee sprain. No timetable was given for his return or whether tight end Marcedes Lewis, who was not in uniform against the Chiefs due to a calf strain, might be able to practice this week.

You can follow Ken Hornack on Twitter @HornackFSFla or email him at khornack32176@gmail.com.