The Tampa Bay Buccaneers are scheduled to face seven of the NFL's 10 highest-ranked run defenses this season, including the fourth-ranked 49ers' on Sunday at Candlestick Park.
"Their front seven is the best we're going to see all year," Bucs quarterback Josh Freeman said of the 49ers, who allow an average of 74 yards rushing per game.
The 49ers' pass rush hasn't been too shabby, either. It's produced nine sacks along with other pressures that resulted in injuries to quarterbacks Tony Romo (fractured ribs) and Michael Vick (dislocated finger).
That 49ers defensive front likely will be without its interior anchor for the first time this season. Nose tackle Isaac Sopoaga is listed as doubtful because of a reported staph infection. Ricky Jean Francois would start in Sopoaga's place, and he'll be surrounded by a strong cast.
"It starts in the middle with Patrick Willis. He's a beast," Freeman said. "Obviously Justin Smith is a stud who gave us issues last year. They're a very physical defense. On the back end, their defensive backs are extremely talented."
Those compliments flowed before Freeman learned that the 49ers have not allowed a 100-yard rusher in 26 consecutive games. Next to test that streak is second-year back LeGarrette Blount, who's rushed for 294 yards, including 127 in Monday night's 24-17 win over Indianapolis.
"We like playing a team that's good at the run, and it's basically a challenge for our front seven," Jean Francois said. "A lot of people are saying we haven't played as many great rushers, but this game I give the guys respect. This is probably one of the best rushers in the NFL for a young guy."
Blount had 26 carries for 82 yards in Tampa Bay's 21-0 win Nov. 21 in San Francisco.
"He's a young guy but runs the ball hard and finds a way to get positive yardage," Willis said. "He had some good runs against us last year. But it's a new year, new football team, new defense."
Eight of Freeman's 16 career wins have come via a fourth-quarter comeback or in overtime. Not only is he a proven closer but he also is an elusive one. He's been sacked six times for minus-33 yards this season. Forty-Niners coach Jim Harbaugh said Freeman is "a big, physical, strong-armed, intelligent guy. Very hard to get on the ground, very hard to rattle. He's a very Ben Roethlisberger-like kind of guy."
In Harbaugh's preseason NFL questionnaire, he listed Buccaneers backup quarterback Josh Johnson as the "best pure athlete" he's coached. Johnson played under Harbaugh at the University of San Diego. What does Freeman think of his understudy? "He understands the game, sees the field extremely well," Freeman answered. "Watching film, he knows the nuances of defenses. It's really been a pleasure and great for my development having him on my team." Freeman has started 29 straight games since replacing Johnson in the fourth quarter of an Oct. 25, 2009, blowout loss to New England.
CB Shawntae Spencer practiced Friday in a limited fashion after being sidelined by a toe injury the previous two days.
Guards Mike Iupati (neck) and Adam Snyder (hamstring) are probable for Sunday, as are wide receiver Michael Crabtree (foot) and running back Frank Gore (ankle).
Buccaneers cornerback Aqib Talib participated fully in Friday's practice. He missed Thursday's session with a knee injury and is listed as probable for Sunday.