''I got the feeling again watching the tape, I use the term, `don't play not to make a mistake, don't tackle being afraid to miss the tackle, be more attacking,''' he said. ''I felt that's where our problems were. We weren't, `Go get `em.'''
The 49ers (3-7) made tackling miscues and surrendered 508 yards and 28 first downs in the 29-13 loss at Seattle on Sunday. San Francisco also gave up 209 yards rushing to a little-known rookie running back named Thomas Rawls, who shined on a day Marshawn Lynch sat out with an abdominal injury.
''I know who he is now,'' safety Eric Reid said Monday.
So, not being aggressive for the typically stout San Francisco defense? That's such a strange phenomenon at this stage of the season, when the team was fresh following its bye week, and in a league that thrives on that style of play.
Reid said when he learned Lynch wouldn't play, he immediately gave the 49ers' defense an ''advantage.'' He hardly figured Rawls would beat them. Let alone dominate them.
''We did a poor job,'' Reid said. ''It just comes down to execution. It's plain as day to see when you don't execute what you're supposed to do as a player, the game kind of gets away from you. When you hear that Marshawn is down, the immediate thought is, `We have the advantage here,' so in my own mind I'm thinking we make them one-dimensional.''
Yet like so many other weeks this season - after all of the losses - Tomsula seems unsure how to fix all the issues on both sides of the ball. His proposed solutions sound familiar as little changes from week to week.
''A lot of it is in your preparation, a lot of it is in your mindset,'' said the first-year coach, who was promoted from his defensive line duties to replace Jim Harbaugh.
Now, it's a real possibility the 49ers will be searching for another new coach come season's end given CEO Jed York's comments that nothing short of winning Super Bowls is good enough around here.
Some are questioning whether Tomsula himself was aggressive enough in a fifth straight loss to the Seahawks, which dropped the Niners to 0-5 on the road this season. He chose to punt on fourth-and-eight at the 11 with 3:09 remaining and his team trailing by 16.
Tomsula defended that decision.
''You have to throw. If it's 4th-and-2, 4th-and-1, we've got a little something there. But, we're 4th-and-8 on the 11 and defensively you're going to pin your ears back, here we come,'' he said. ''You're going to be under duress and it's a long conversion. So, if that doesn't happen right there now you've got a three-score game. There is no time. That's quite frankly the way I see it.''
It doesn't get any easier going forward. NFC West-leading Arizona (8-2) visits Levi's Stadium on Sunday after pounding the 49ers 47-7 in Week 3 - on a day demoted quarterback Colin Kaepernick threw four interceptions, with two of those returned for touchdowns.
''Well, you believe in the people that you have. That locker room there and the guys that are in it, there's good, determined, good football players in there,'' Tomsula said. ''We've just got to keep pounding through it and get to the other side.''
NOTES: DT Glenn Dorsey, hurt on San Francisco's first defensive snap of the game, was undergoing an MRI on his injured right knee. It could be a season-ending injury if he tore his anterior cruciate ligament. ... WR Anquan Boldin and DB Jaquiski Tartt were getting treatment in the trainer's room Monday. ''We think they're going to be all right,'' Tomsula said. ... With Kaepernick headed for surgery on his non-throwing left shoulder, the team was bringing in a quarterback for a workout. Tomsula said that last Monday was the first he heard of Kaepernick's shoulder pain.
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