Bill Fitch isn't taking any chances.

The Boston coach says he is not looking past the Houston Rockets to a possible showdown with the Philadelphia 76ers in the next round of the playoffs.

Fitch is so concerned about the Rockets that he has closed practices and invited former Celtic great John Havlicek to work out with the team, "to give us some different looks."

The Celtics, who have been off for 10 days, will play their first playoff game tonight against the Rockets at the Boston Garden.

The second game of the best-of-seven Eastern Conference semifinal series will also be in Boston Friday night.

The Celtics, who finished with the best record in the National Basketball Association at 61-21, earned a bye in the first round of the playoffs. The Rockets beat the San Antonia Spurs, 2-1, in a best-of-three first-round series.

The Rockets had a 41-41 regular-season record, the poorest to teams still in the playoffs.

The Rockets also lost the six games they played against Boston this year, but it hasn't dampened their spirits.

The Rockets are perhaps as close to a one-man team a any in the league, relying on center Moses Malone, who was second in the NBA in rebounding and fifth in scoring, the only player to be in the top five in those two categories.

"If we control the tempo and Moses can take charge, it could be interesting," said Coach Del Harris, "but everyone is expecting Boston to blow us away. I don't think that'll happen."

The 10-day rest should help the Celtics. Four of their top players were nursing nagging injuries.

Dave Cowens had a sore big toe, Larry Bird a bruised thigh, Cedric Maxwell a sprained ankle and M.L. Carr a sore wrist. All are fit now.

In the other Eastern Conference semifinal series, the 76ers hold a 1-0 lead over the Atlanta Hawks going into their second game today at the Spectrum at 3 p.m.

The early start is because the Philadelphia Flyers hockey team will play at the Spectrum tonight and it's supposedly easier to take the basketball floor down than it is to put it up.