49ers defense thrives vs. Patriots under Fred Warner, but his injury looms large

At the half of this Week 4 afternoon game, the San Francisco 49ers lead the New England Patriots by a score of 20-3.

Much of the Niners' success is due to the performance of their defense. After three games to start this season, San Francisco's offense had been playing like a top unit.

The defense, however, was a different story, giving up big plays in two games in which the team lost by only one score in each.

Against a Pats team struggling on offense, the 49ers defense was due for a big game.

It couldn't have come at a more needed time.

The defense, led by All-Pro linebacker Fred Warner, has been aggressive from the jump. Warner headed into the half as the team leader in tackles with seven total.

Warner's most impactful play, though, was his pick-six in the second quarter. He masterfully covered the middle of the field and picked off Patriots quarterback Jacoby Brissett. He then turned on the jets and scored the game's first touchdown with his 45-yard return:

Warner's teammates on defense have also put on great first-half performances. Newcomer on the defensive line Sam Okuayinonu made his stamp on the game with a forced fumble in the first quarter.

The defensive line has also gotten to the quarterback consistently in the first half of this game. Defensive tackle Kevin Givens picked up 2.5 sacks in the first half, and other defensive tackle Maliek Collins had 1.5 sacks.

Fred Warner suffers ankle injury, concerning 49ers defense

Right before halftime, though, Warner disappeared into the locker room along with tight end George Kittle.

It was made immediately clear why both Warner and Kittle exited, although the Niners subsequently listed both players as questionable with respective injuries:

While San Francisco has a comfortable lead, it clearly needs Warner's presence on the field, both as a leader and as a key playmaker.

One can hope he's able to return soon, and he was seen on the sideline wearing a helmet at the start of the third quarter.

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