Travis d'Arnaud's hot streak -- three home runs and two doubles in his previous eight games -- has made a believer of Mets manager Terry Collins.

"I think what we're seeing is exactly what people said: This guy is going to be dangerous," Collins said before Thursday night's game.

After Thursday night's game, D'Arnaud was batting .273 with 10 doubles, seven homers and 21 RBIs since returning from Triple-A on June 24.

Collins said Las Vegas hitting coach George Greer challenged d'Arnaud to hit a double every time up. "That means attack the ball," Collins said. "He's done it, and I think it's paid off for him."

Homer disparity

The sound alone told the story: The Citi Field crowd's collective voice rose -- then fell in disappointment -- when a drive by the Mets was caught at the warning track.

advertisement | advertise on newsday

The Nationals didn't have that problem. They outhomered the Mets 7-1 in their three-game sweep and outscored them 14-4.

Collins said getting upstaged in his team's own ballpark was disappointing. "The whole difference is we can't keep the ball in the park and we can't hit them out," he said. "That was the story of this series for sure."

Slow ride

Patience at the plate, Collins said, has been a recent struggle for the Mets. He said he has talked with his players about slowing the game down when play and adrenaline speed up.

"It's easy to say, it's hard to do," he said. "These games are not played by robots. When emotions start to get high, you've got to slow them down a little bit. When you have young players, sometimes that can be difficult.''

The rule

Baseball's Rule 7.13 has had some growing pains, with the emphasis on "pains" for Collins and the Mets. A day after Matt den Dekker, representing the tying run, was called out at the plate in the ninth inning against the Nationals, Collins was unclear on the consistency of the rule, which forbids a catcher who does not have possession of the ball from obstructing a runner's scoring lane.

Collins said to the umpires before a review of the play: "I want you to look at this. I have absolutely no idea if he's out or safe. None. But you've got to look at it." The out call then was upheld.

Collins called the rule a "work in progress" and trusts it will be less confusing next year.

Abreu back

advertisement | advertise on newsday

Bobby Abreu doesn't have to think about retirement just yet. After being designated for assignment by the Mets 10 days ago, Abreu, 40, will report to Triple-A Las Vegas. He was sent to Las Vegas on March 31 when the Mets originally signed him.

Wright track

David Wright may not be hitting for power, but he extended his hitting streak to 13 games, the longest of his career, with a single in the bottom of the first inning Thursday night. He entered the day batting .320 with four RBIs in his previous 12 games.

Extra bases

Daisuke Matsuzaka's next rehab start will be with Double-A Binghamton on Saturday in Reading, Pennsylvania.