Christian McCaffrey has been a talented yet brittle performer during his NFL career.

But the San Francisco 49ers running back made it clear Thursday that he will play in Sunday's NFC Championship Game against the host Philadelphia Eagles.

McCaffrey missed his second straight day of practice due to a right calf injury but had a one-word answer when asked the chances of him missing the game against the top-seeded Eagles.

"Zero," McCaffrey said.

McCaffrey is focusing on the mental part of the game and studying the possible plays. He also is taking part in walk-through portions of practice.

"It's the same process for me, just lowering a little bit of the physical load," McCaffrey said.

McCaffrey has been a solid contributor for the second-seeded 49ers since being acquired from the Carolina Panthers in mid-October.

He rushed for 746 yards and six touchdowns in 11 regular-season games for the team and also caught 52 passes for 464 yards and four scores. He has scored at least one touchdown in the past eight games, the top such streak of his six-year career.

San Francisco has won all 12 games McCaffrey has started, including playoff victories over the Seattle Seahawks and Dallas Cowboys.

He ripped off 119 yards on 15 carries and had a touchdown reception against the Seahawks in the NFC wild-card round but was limited to 35 rushing yards and one score on 10 carries in last Sunday's divisional round over the Cowboys.

Adding to the anxiety over the running game is that No. 2 back Elijah Mitchell (groin) also missed his second straight practice on Thursday.

Coach Kyle Shanahan expects Mitchell to be available against the Eagles.

The San Francisco running game will surely be counted on Sunday to help take pressure off rookie quarterback Brock Purdy, who has won all seven of his NFL starts.

The 49ers will want to slow a potent Eagles' pass rush that is enjoying a historic campaign.

Counting the postseason, the Eagles have racked up 75 sacks, third-most in NFL history. The only two higher outputs came from the mid-1980s Chicago Bears, who had a record 82 in 1984 and 80 in 1985.

Eagles linebacker Haason Reddick (16 sacks), defensive ends Brandon Graham (11) and Josh Sweat (11) and defensive tackle Javon Hargrave (11) all established career highs for sacks. The defense also includes tackle Fletcher Cox (seven sacks) and safety C.J. Johnson-Gardner, who tied for the league lead with six interceptions.

"They fly to the ball well. They have a good pass rush," McCaffrey said. "For us, it's about executing the play call, though.

"Kyle knows all that stuff, and he knows exactly where he wants to go with the ball. It's just up to us to be able to do it at full speed and play beyond the X's and O's."

While the Eagles ranked second in total defense (301.5 yards per game) during the regular season, San Francisco was even better as it led the NFL in total defense (300.6 yards per game) and scoring defense (16.3 points per game).

Defensive end Nick Bosa (NFL-high 18.5 sacks) is a finalist for Defensive Player of the Year honors, while linebacker Fred Warner (130 tackles) topped 100 stops for the fifth straight season.

Warner is also known as one of the NFL's better on-field talkers and that includes barbs directed toward his teammates.

"Fred is always going to talk because he's a true leader," Shanahan said. "Fred should be the guy who talks because of the way he carries himself every day. Everyone knows how good of a player he is but when it comes to what he does day-in, day-out since he's been here ... he's ahead of everybody."