First, he set up Brooks Laich's tying goal in the final minute to force overtime against the New York Islanders, then two nights later scored the game-winning tally with just minutes to play against the St. Louis Blues.
As the Capitals have moved into first place in the Southeast Division with five straight wins, the team appeared to be on the verge of a breakthrough.
However, the team may have suffered a major setback when Nicklas Backstrom went down with an injury in the second period of Monday night's tilt against the Tampa Bay Lightning.
Backstrom has been playing through a fractured thumb for a few weeks now, but if the injury forces him to miss any significant length of time, the team will be in trouble. If the past few Stanley Cup playoffs have taught us anything, it's that being deep at the center position leads to postseason success.
The good news for the Caps is that they're more prepared to deal with Backstrom's absence than they were 10 days ago. The addition of Arnott gives the team two viable scoring-line centers, which they haven't had since Sergei Fedorov's departure (which is no slight to Brendan Morrison or Eric Belanger).
Arnott's presence also seems to have ignited the passionate play of Alexander Semin, who has been a difference maker over the course of the five-game winning streak.
Needless to say, the deadline day moves of GM George McPhee are paying dividends for the Capitals, but both Arnott and Dennis Wideman are being thrust into larger roles.
Wideman has been playing more and more in order to make up for Mike Green's absence, and now Arnott may have to serve as a stopgap until Backstrom is able to return.
Backstrom is the type of player who plays in all situations, so his absence is a difficult one for the Capitals to cope with. Arnott is likely capable of filling the void on the power play and at even strength, but Backstrom is a key penalty killer, as was David Steckel, whom the Capitals dealt for Arnott.
With the gap between Washington and their closest Southeast competitor in Tampa Bay at two points, every game is critical and the Capitals can only hope that their No. 1 center and their No. 1 defenseman return soon.