ALLEN PARK -- Jim Schwartz said Reggie Bush isn't a mudder, after the Detroit Lions tailback struggled with the slick playing surface during Sunday's loss in Pittsburgh.

Reggie, your thoughts?

"I think the opposite," he said.

And he has reason to think that.

Reggie Bush had his worst game of the season against Pittsburgh, but denies his coach's assertion that he's not a mudder.

Bush has never rushed for more yards than he did during a 2011 game in Buffalo, when he plowed through persistent snow flurries to gain 203 yards. And his best receiving game came in the 2006 season at Soldier Field, when the windchill was 13 degrees and snow fell throughout the game.

He had 132 yards receiving that game -- which happened to be for the NFC championship -- despite the torn-up field.

"I wasn't aware of that," Bush said. "That just makes me more depressed."

The reason he's depressed is he's coming off the worst full game of his Lions career. He rushed 12 times for just 31 yards Sunday against Pittsburgh, and seemed to struggle several times with his footing on the muddy playing surface.

It rained throughout the day at Heinz Field, creating the slick conditions.

Bush said he wore the right cleats, with extra-long spikes, but struggled a bit with his balance and cutting over-aggressively.

He was benched for one second-half stretch in favor of No. 3 tailback Theo Riddick.

"It's very frustrating, because I want to be out there making plays," Bush said. "It's been on my mind ever since, and it should sting. It should hurt. It shouldn't feel good."

Bush acknowledges he struggled in that game, but Schwartz took it a step further Monday when he indicated Bush has consistent struggles in inclement weather. He said Bush was not a "mudder," horse-racing parlance for struggling on a muddied track.

"He's an explosively quick guy," Schwartz added. "He's better on a fast track."

Bush disagreed with that notion.

"I pride myself on being able to run in all conditions. Know what I mean?" he said. "I think running in those kinds of conditions is, for me, it's better, because now defenders need to constantly be on their heels and toes. And when you can get guys off balance in the mud and when it's raining, it's kind of an advantage to the running back.

"So I think (against Pittsburgh), just didn't do a good job at running balanced, so to speak, and keeping my feet underneath me. I just didn't handle the situation well."

Several players, including quarterback Matthew Stafford, backed up Bush. Stafford cited Bush's 105-yard game two weeks ago in Chicago as an example.

But Bush did struggle with his ball security, and knows there's no excuse for that, inclement weather or not.

"As a running back, that's a cardinal sin, and I know that," said Bush, who has fumbled twice in three games. "I've been in this league long enough, and playing football long enough, to know that. I got to do a better job this week, and it'll get done.

"I've had my back against the wall before, and I'll be all right."