By SANTOSH VENKATARAMAN
STATS Senior Writer

The Tennessee Titans may be a different team with Vince Young
re-installed as the starting quarterback and Chris Johnson
coming off the best game of his career.

San Francisco's Alex Smith can relate to Young as far as being a
high draft pick trying to resurrect his career after a difficult
start.

Young and Johnson look to help the Titans earn a second straight
victory when they try to hand the banged-up 49ers a fourth
straight loss Sunday.

Tennessee earned its first win last week, beating Jacksonville
30-13. Young, named the starter after Kerry Collins guided the
Titans to an 0-6 mark, responded by completing 15 of 18 passes
for 125 yards and a touchdown.

It was Young's second start since 2007.

"He looked all right out there," owner Bud Adams said about the
No. 3 overall pick in the 2006 draft. "I think he's coming
around a lot. I think there's some things that happened to him
early in his career that didn't let him concentrate on football.
I think he realized he needed to work at it hard. And he has
shown that."

While Young was steady, the Titans' first victory was really
keyed by Johnson. The second-year running back rushed for a
franchise-record 228 yards on 24 carries and scored two
touchdowns.

Johnson leads the league in rushing with 824 yards after
entering last week fifth. His five runs of over 40 yards also
lead the NFL.

"It feels real good to look at some of the guys who have played
before me, then come in and break a record," Johnson said. "But
records are made to be broken."

Young improved to 19-11 as a starter, and he's 6-2 against NFC
clubs. In contrast, Smith is 11-20 after he lost his first start
since 2007 last week, 18-14 at Indianapolis.

Smith - the top overall pick in 2005 - played well in relief of
Shaun Hill on Oct. 25 in a 24-21 loss at Houston, throwing three
touchdowns to tight end Vernon Davis to rally the 49ers (3-4)
from a 21-point deficit.

He completed 19 of 32 passes for 198 yards against the Colts
with one touchdown to Davis and one interception, falling to 3-6
in starts against AFC teams.

"I thought Alex did very well," coach Mike Singletary told the
49ers' official Web site. "I was very pleased to see him make
some throws. I was very excited and anticipated this game for
him because I knew the rush was going to be coming at him."

Singletary received bad news Monday when he learned that
cornerback Nate Clements and left tackle Joe Staley will be out
for this game.

Clements, who has missed only one game in his career, has a
broken right shoulder blade and is out for up to eight weeks.
The 49ers signed cornerback Keith Smith on Tuesday.

Staley has a sprained right knee and will miss a game for the
first time in his three-year career. Barry Sims is expected to
take his place in the lineup.

"Obviously we're going to miss Joe Staley," Singletary said. "In
terms of how it's going to affect our offensive line, which in
essence is how it's going to affect our offense, you find a way
to win. You find a way to work around it.

"Obviously he will be missed. We think a lot of Joe Staley. I'm
hoping he's back real quick because he helps us tremendously. At
the same time I know our offense will continue to get better."

Singletary has said he will go with the best players who give
the team a chance to win even if it means he has to regularly
shake up the lineup.

"This team right now is going through some changes," Singletary
said. "You're seeing guys step up, young guys stepping up, and
some other guys stepping back. It's going to continue to be that
way. I believe in the best 11 guys on the field. Whoever that
is, that's who's going to be out there."

San Francisco appears to be fairly healthy up front on defense,
and that will be important as it tries to contain Johnson. The
49ers have the league's second-ranked rush defense, allowing
84.9 yards per game.

The Titans won 33-22 at home in the last meeting Nov. 27, 2005.