Bears' defense cautiously optimistic after throttling Raiders

There’s little doubt that Andy Dalton, A.J. Green and the Cincinnati Bengals offensive line will put up more resistance than the Bears got from the Oakland Raiders on Friday night. Regardless, the impressive defensive performance was seen as a sign of progress.

‘‘I think we played great,’’ safety Chris Conte said. ‘‘Mel [Tucker] was telling us we had a bunch of three-and-outs. It seemed like a good night. But we’ll watch the film and see how it really want.’’

The Bears’ first team defense held the Raiders to 92 yards on 25 plays in the first half. Tim Jennings and nickelback Isaiah Frey had interceptions. Charles Tillman had a sack on a cornerback blitz. Julius Peppers, playing for the first time in the preseason, had a tackle-for-loss that helped set up Jennings’ interception.

‘‘I think I’m ready. This whole team is ready,’’ Jenning said. ‘‘The good thing is we’ve got another week to get better. I don’t know how the coaches are going to play it out, whether they’re going to have us sit out [against the Browns on Thursday]. But this week of practice we’re going to prepare like we’re going to play. I don’t know how much, but we have another week to get better and that’s the mindset we’re going to go into this game with.’’

But it’s still the preseason. The question remained after the game: Just how good is this defense?

It’s so hard to tell,’’ Conte said. ‘‘It’s really yard to tell until you get into that first game. the good thing is that we’re doing well and there aren’t big issues that are negative. There aren’t a lot of negative things that we’re worried about. It’s all pretty positive at this point. I think we’re getting better. I know we have tons of talent and we can be a great team, but it’s really hard to say exactly how good.’’