The natural reaction to losing a No. 1 goalie to injury would be to adjust the system to a more conservative approach to give an added layer of protection to the backup being asked to carry a heavier workload.

The Pittsburgh Penguins can't fall into that trap.

Goalie Marc-Andre Fleury will miss at least the Wednesday Night Rivalry game against the Boston Bruins at TD Garden (8 p.m. ET; NBCSN) because of a concussion, the Penguins said Wednesday. His absence shouldn't stop the Penguins from building on the game they played Monday, when they offered a glimpse into the attacking, up-tempo, high-risk, high-reward team they are likely to be under new coach Mike Sullivan, who replaced Mike Johnston on Saturday.

Yes, the Penguins lost 4-1 to the Washington Capitals, a fact that can't go unnoticed, especially with Pittsburgh not holding a Stanley Cup Playoff spot in the Eastern Conference standings. But these were not the same Penguins we have seen this season.

For the first time in a long time, the Penguins started to look like the team they're built to be. They're not constructed to try to win games 2-1, which they attempted to do too often under Johnston. They have the offensive talent to outscore most of the teams in the NHL, likely to come out on the right side of a high-scoring game more often than not.

The Capitals took advantage of a couple of early defensive miscues to take a 2-0 lead, but if the Penguins play like they did Monday, they'll start scoring and winning.

They were crisper is their breakouts, a major point of emphasis from Sullivan. They were able to get the puck deep into the zone and work behind the goal line to set up scoring chances. They had more pressure, more puck possession, and more scoring chances.

The Penguins took a season-high 45 shots on goal; they outshot the Capitals by 11. Pittsburgh attempted 89 shots, 64 at even strength, according to war-on-ice.com. Washington attempted 52 total, 37 at even strength. There were 29 even-strength faceoffs in Pittsburgh's offensive zone; 13 in Washington's offensive zone.

All of those numbers suggest a positive turn for the Penguins, who coming into the game had a 48.4 SAT percentage and were starting in the offensive zone 15.6 times per game.

The main reasons the Penguins lost were missed coverages on the first two goals and another scintillating performance from Capitals goalie Braden Holtby, who is 11-0-1 in his past 12 starts.

All teams are going to run into a hot goalie on occasion. Give some credit to the goalie, but also try to figure out why he was so hot. In Pittsburgh's case, Sullivan said the Penguins didn't do a good enough job disrupting Holtby's field of vision.

The missed assignments (not picking up Nicklas Backstrom on his goal, and inexplicably giving John Carlson a second shot off the rebound for his goal) must be corrected. They're inexcusable.

Overall, the Penguins were better and more fun to watch than they were under Johnston.

Sidney Crosby was dynamic on some shifts, involved in multiple Grade A scoring chances. Sullivan and Crosby should try to bottle the first shift of the game. That's how good it was. Evgeni Malkin scored and looked dangerous. Patric Hornqvist, Chris Kunitz and Beau Bennett, before he was injured, had chances.

Pittsburgh needs more out of forward Phil Kessel and its power play, which will remain a work in progress until Sullivan can find the right fit for all the pieces and convince the players to shoot the puck.

Defenseman Brian Dumoulin played an NHL career-high 26:11 and looked good. He won't play that much when Kris Letang comes back from an upper-body injury, and Trevor Daley, who arrived Monday in a trade from the Chicago Blackhawks, gets comfortable, but he looks like a good complementary player for the style the Penguins should be using.

Daley is a puck-mover who last season scored 16 goals (with an uncharacteristically high 14.2 shooting percentage) for the Dallas Stars. The Penguins needed another puck-mover. With Letang, Olli Maatta, Daley and Dumoulin, their defense will be among the more mobile in the League.

Derrick Pouliot has the tools to add to the mobility when he is recalled from Wilkes-Barre/Scranton of the American Hockey League.

The result wasn't good against Washington, but there were positive signs and a foundation from which to build.

It'll be detrimental if the Penguins get cautious and revert to the low-risk, low-reward style they played under Johnston because they lost the first game under Sullivan and Fleury is injured.

---