Tuesday in Detroit, the Washington Capitals turned in their first sad-sack performance since Christmas. Considering that it was their 16th game in that stretch, it was not hard to accept the 4-3 defeat.

The reason should be fairly obvious. The Capitals had played two emotionally charged games with the New York Islanders Saturday and Sunday, and could not stir themselves sufficiently for the mediocre Red Wings, who ended their seven-game winning streak.

The wonder is that the Capitals have been able to avoid collapse in similar circumstances. For example, they slipped past Hartford, 3-2, Dec. 29, following back-to-back victories over Philadelphia and the Islanders.

Another surprise is the way the Capitals' seven-man Canada Cup contingent has avoided a midseason letdown. During training camp, Coach Bryan Murray predicted the need for a midseason rest for those whose long, long campaign began in early August.

So far, it has not been necessary, although Canada Cup participation has been shown to have had a major negative effect on at least two players, Bengt Gustafsson and Peter Andersson.

Certainly, the team's one-two offensive punch of Bob Carpenter and Mike Gartner has experienced no letup after leaving Canada Cup competition on a high note.

"I feel really good physically and, of course, mentally I feel great, the way things are going," said Carpenter, an All-Star selection whose 39 goals are only two short of the NHL high for a U.S.-born player, set last year by Joe Mullen of St. Louis.

"At times I've felt tired, particularly after long trips, but once I get home and rest, I'm okay. My weight is 192, which is my highest ever. I usually lose a lot and last year I was down to 183 or 184, but this year it's stuck."

"The Canada Cup has had no effect on me yet, either physically or mentally," said Gartner, who has 31 goals following his gold-medal exploits with Team Canada.

Successive bouts with flu and bronchitis have trimmed Rod Langway's weight from 215 to 204, but when asked if he felt his physical problems had any relation to the Canada Cup, the All-Star defenseman replied:

"Of course not. It has nothing to do with my ice time, either. I'm just playing a normal shift. The way everybody's doing a job out there, nobody has to work overtime."

One who was affected by his Canada Cup play was Dave Christian, who managed only three goals in the first 19 games before regaining his form of last season.

"It definitely was a factor early in the season, not so much physically as mentally," Christian said. "But right now, I feel as good as ever and I hope the effects are over."

Bryan Erickson has slumped in recent weeks, with only one goal in 12 games. However, the dropoff seems more attuned to his fourth-line assignment than to any long-term considerations.

"This is all really still new to me," Erickson said. "I feel good, and even though it looks like I've had a letdown, I don't think that's it."

There is no question about the negative fallout that affected Gustafsson and Andersson.

Gustafsson incurred a severe hamstring pull during the Canada Cup. After aggravating it twice, he sat out six weeks while it healed.

"Other guys have such a long season, but now that I had that break it should help me now," Gustafsson said. "I hope it will, because it was no fun sitting and watching all those games. But I feel good and the way the team is winning, it's fine."

Andersson recently returned from a 10-day tour with minor league Binghamton, after he proved a major disappointment over the first half of the season.

"Maybe the first 20 games I was a little tired and too relaxed after the Canada Cup," Andersson said. "Then I wasn't getting as much ice time and I lost my confidence. That's what I have to get back."

The Capitals' next assignment is a home game Friday against Toronto. It will be Washington's first meeting this season with the Maple Leafs, who are owners of the worst record in the National Hockey League.