INDIANAPOLIS (AP) While the Indiana Pacers may have the best record in the Eastern Conference, coach Rick Carlisle doesn't like what he sees with his team's defensive efforts over the last five games.

``It's pretty clear that on nights where we don't bring a certain type of defensive disposition, we're going to struggle and often times we're going to lose,'' Carlisle said Thursday.

And Indiana is struggling against teams with losing records.

The Pacers (19-7) are 3-2 in their last five games, all against sub-.500 teams, including Wednesday night's 94-90 loss to the 5-21 Orlando Magic, a team that lost 19 games in a row earlier this season.

``When you're one of the top two teams in the league in (fewest) points allowed, and you give up 94 on your home court, you've forgotten who you are,'' Carlisle said. ``We've got to re-identify the type of team we are. We have to be a defensive team first.''

To illustrate his point, Carlisle pointed to a few telling statistics. In games they win, the Pacers hold their opponents to just over 81 points a game and have a rebounding advantage of four.

When they have lost, the Pacers allow 91 points a game and are out-rebounded by about 5.5.

``There's no explanation for that, other than consistency of sustained effort,'' Carlisle said.

That effort will have to be there Friday, when Indiana hosts the Detroit Pistons, the team which Carlisle coached to back-to-back 50-win seasons before he was fired this summer.

Unlike Indiana's recent opponents, the Pistons are 15-10 and just snapped a four-game losing streak with a victory over the Chicago Bulls, the same team the Pacers lost to on Saturday.

``They're going to come in here and they're going to be willing to brawl for a win,'' Carlisle said. ``They're going to fight to win, and we have to get back to fighting. We have to be a more determined team, particularly at the defensive end.''

Carlisle challenged center Jeff Foster specifically. After a strong beginning to the season in which he took the starting job from Scot Pollard, Foster has spent more time on the bench as Carlisle has opted to go with Jermaine O'Neal, Al Harrington and Ron Artest in the front court.

``Foster's minutes have dropped off in recent games because his energy has dropped off for some reason,'' Carlisle said. ``That can't happen.''

Pacers guard Anthony Johnson says the team needs to start having more fun on the court.

``We just have to know that every day in the NBA is a good day and be appreciative of that,'' Johnson said. ``Then we'll start relaxing and playing the game we know how.''

Johnson's point intrigued Carlisle, who said the fun would return when the success did.

``To me fun is winning,'' Carlisle said. ``And right now I'm not having much fun. In the last five we've slipped down and we have to notch it back up quickly, otherwise a team like Detroit will make us look bad.''