For 19 straight games over six weeks, there was little doubt about which defensemen Washington Capitals Coach Bruce Cassidy would utilize. Cassidy was married to his choice of six defenders, with longtime minor leaguers Jason Doig and Joel Kwiatkowski forming his third pair. But now, with their play slipping and the playoffs fast approaching, Cassidy is mulling over some changes.

Tampa Bay continues to push the Capitals for the Southeast Division lead, making each game vital and forcing the rookie coach into difficult decisions. He must weigh whether Doig and Kwiatkowski -- who played for Cassidy in the minors, were acquired for virtually nothing and have never been in an NHL playoff game -- will be able to handle the pressure of this time of year. He also must decide when or if to give veterans a breather and whether to put backup goalie Sebastien Charpentier back in net (he might start Sunday).

The coaching staff hoped its defense would not become an issue, but Kwiatkowski has not been as solid in recent games and his performance Wednesday night helped Buffalo score two late goals and nearly pull off what would have been a three-goal comeback. Doig has been more consistent and provides a physical element, but he is also inexperienced at this level, which could re-open the competition for those final lineup spots.

"Those two guys have played down a notch, Kiwi and Doig," Cassidy said. "I thought in my mind they were the two best guys for the job before, and that's the decision I made. Now, I think Kiwi is showing signs of being a young guy struggling with his consistency lately, and that's something we want out of that last pair."

General Manager George McPhee wants to add an established defenseman prior to the March 11 trade deadline, sources said, which would surely alter the mix, and Ken Klee, who is having a career season, could return to the lineup tonight in New Jersey from his back ailment, which would restore order to the top two pairs (Klee and Sergei Gonchar; Brendan Witt and Calle Johansson). If Klee plays the most likely scratch will be Rick Berry, who did well in three appearances after not playing for six weeks.

McPhee and Cassidy discussed the defense yesterday and are considering when to activate defenseman Jean-Francois Fortin (back spasms) from the injured reserve list, which would require sending another player to the minors (most likely enforcer Stephen Peat). That move is not expected to come until Sunday at the earliest -- Fortin is practicing and eager to play after last dressing for Washington on Dec. 30 -- and Cassidy said yesterday that he wants to get the 23-year-old back in the lineup soon.

"Of course I really want to play," Fortin said. "I've been patient and it has been tough, I'm not going to lie to you. It's been really tough. Everything went so well last year, and this year everything has been the opposite, but I haven't lost my confidence, and I'll be ready for sure."

Cassidy is debating whether to scratch Kwiatkowski, sending the message that his spot in the lineup must be earned. But he is expected to pair Doig, 26, and Kwiatkowski, 25, again for tonight's game.

Keeping Berry and Fortin out of games for so long could prove risky, however.

It is difficult for players to retain confidence and maintain game-specific skills when they are scratched for months at a time, and, with injuries to defensemen common, it is tough to throw them back in at short notice and expect mistake-free results. Fortin, who was outstanding as a rookie last season, has not been given much of a look in the second half after a strong start. Berry, 24, was selected 55th overall in the 1997 draft, has played 128 NHL games (far more than Doig, Kwiatkowski or Fortin), prefers a simple style and is quick to defend teammates on the ice, but was scratched for 16 straight games and would have been out longer had Klee not been injured.

"You go through a lot of mental battles with yourself," Berry said. "You wonder, 'Am I not good enough to make the lineup?' But at the end of it all you end up believing in yourself and believing you should be in and believing you are a good player. And I think that's what it takes, because it comes from within."

Washington's third defensive pairing of Jason Doig (getting upended here) and Joel Kwiatkowski may be demoted.