The Cleveland Cavaliers have clinched a playoff spot, but they aren't playing like a team headed for the postseason.

Looking to avoid their fourth loss in five games, the Cavaliers on Sunday meet lowly Miami and will try for just the second season series-sweep of the Heat in franchise history.

Since clinching a playoff berth on March 29, Cleveland has split six games. Heading into the final week of the regular season, the defending Eastern Conference champion Cavaliers (43-36) have just a two-game lead over Washington for the No. 4 seed in the Eastern Conference.

Cleveland's inconsistency down the stretch is frustrating its best player.

"We have to get better," said LeBron James, averaging a league-high 30.3 points per game. "We can't worry about what Washington does, what Philly does. We have to play well. I know how important the postseason is. I've won playoff series. I've won playoff games. I know how important the postseason is."

James is averaging 27.1 points over nine career games in Miami, but the Cavaliers have lost eight of them.

Though he scored 34 on Friday, Cleveland lost to Chicago for the second time in eight days, 100-95. James had 24 in the first quarter - tying his own franchise record set earlier this season - but the Cavaliers trailed 53-47 going into the break never led in the second half.

"Something has to change in order for us to go into the playoffs the right way," said coach Mike Brown, whose team has lost nine of its last 11 road games.

Now, the Cavs are trying to sweep Miami (14-65) in a season series for the first time since taking two games in the Heat's inaugural season in 1988-89. James was the key in both wins so far in 2007-08 - he had 25 points and 12 assists in a 96-82 home win on Christmas Day, and had 28 on Jan. 21 in a 97-90 victory in Miami.

Dwyane Wade led the Heat with 42 in that game, but was shut down for the season on March 10 to rehab his left knee.

The Heat failed to win back-to-back games for just the second time this season after losing 96-91 to Memphis on Friday. Coming off a 95-88 win over the Bulls on Tuesday, Miami trailed by as many as 19 points and fell short with a late rally.

"As a competitor, you never want to go down like that," said Chris Quinn, who had 14 points, eight assists and seven rebounds. "With three games left, all we can do is play as hard as we can and try to get some wins."

Miami, which will finish the season with the league's worst record, needs to win two of its remaining three games to avoid finishing with the worst record in franchise's history. The Heat, who went 15-67 in 1988-89, will face playoff-bound Toronto and postseason-hopeful Atlanta to close 2007-08.

Copyright 2007 by STATS LLC and Associated Press. Any commercial use or distribution without the express written consent of STATS LLC and Associated Press is strictly prohibited