(Photo credit: Stephen R. Sylvanie-Imagn Images)

Raiders star tight end Brock Bowers has been ruled out of Sunday's game against the Tennessee Titans, marking his second straight absence for Las Vegas due to a knee injury.

Bowers missed practice all week and coach Pete Carroll saw no reason to wait another few days to see if his condition improved.

'We're trying to make sure that once he's back, he stays back, and there's no setbacks,' Carroll told reporters Friday.

Bowers attempted to play last week against the Indianapolis Colts but his pre-game efforts weren't productive and the Raiders made him one of their inactives.

Bowers was a huge breakout star as a rookie last season when he caught 112 passes for 1,194 yards and five touchdowns. The receptions were the most by a rookie in NFL history.

This season, Bowers has 19 receptions for 225 yards and no touchdowns in four games.

Offensive coordinator Chip Kelly said not having Bowers affects the entire offense.

'You lose the premier tight end in the NFL, and play calling is different,' Kelly said. '... You have to be able to make adjustments when you lose players like that, and you've got to move on, because no one's feeling sorry for you when you have a guy down.

'So, that's just the nature of the game, and we're hopeful we'll get Brock back soon here. He's working his tail off to get back in the rehab process, so we'll see how that goes.'

Tight end Michael Mayer (concussion) is expected to return against Tennessee after missing the past two games. He practiced in full and wasn't given a status designation on Friday. Mayer has six catches for 47 yards this season.

Punter AJ Cole (right ankle) returned to practice on a limited basis Friday and is listed as questionable.

--Field Level Media