PHILADELPHIA -- In each of the last two games, the Nationals have surrendered a late-inning insurance run when Phillies runners have been able to take advantage of easy opportunities to get into scoring position.

Friday, Chase Utley walked against Mike Gonzalez before stealing second base and scoring on a Ryan Howard single. On Saturday, Utley was hit by a pitch by Sean Burnett before he stole second and third base without much trouble against Burnett and catcher Kurt Suzuki. Again, Howard drove him in, this time with a sacrifice fly.

"He took some gambles, went first move, and it worked out," first baseman Adam LaRoche said of Utley. "As a team, we need to know who's capable of doing that and keep that in mind in those situations."

Holding runners and throwing out would-be basestealers has been an issue for the Nationals all season -- the Nats entered Sunday's series finale second to last in baseball with a 14 percent caught-stealing rate -- and it's reflected in Suzuki's caught stealing splits since he came over from the A's on Aug. 3.

Suzuki, who has become Washington's primary backstop after also starting regularly behind the dish in Oakland, has a career caught-stealing percentage of 28 percent. In 75 games with the A's this year, he caught 23 of 60 runners (38 percent). Since joining the Nats, he's 1-for-15 (seven percent).

"I mean, the guy was running before [Burnett] even made a move, and he didn't check him," manager Davey Johnson said Saturday night of Utley's steals. "That can't happen. Those are mental mistakes, not physical mistakes."

Backup catcher Jesus Flores, who owns a 25 percent caught-stealing rate, has caught just 12 percent of would-be basestealers this year.

D-backs catchers have caught a Major League-best 47 percent of would-be basestealers.

Isaac causes Nats to alter travel plans to Miami

PHILADELPHIA -- With Tropical Storm Isaac heading toward South Florida on Sunday night, the Nationals altered their travel plans in advance of this week's two-game series that's scheduled to begin in Miami on Tuesday.

The Nats have an off-day Monday, and would normally have left after Sunday afternoon's game in Philadelphia. But, instead, they will stay in Philadelphia and travel to Miami on Monday afternoon.

According to Weather.com, there are Hurricane watches for the Miami area, and the storm is expected to reach that area by early Monday morning. According to the Miami Herald, the storm could turn into a hurricane as it crosses the warmer waters of the Florida Straits and enters the Gulf of Mexico.

More than 500 flights were canceled at Miami International Airport on Sunday, and about 3,700 homes in Miami-Dade county were already without power.

It's Washington's last trip to Miami this season.

Worth noting

• Nats outfielder Michael Morse was able to play catch at Citizens Banks Park without any problems on Sunday morning. He said his right wrist is still a little sore, but he expects to play against the Marlins on Tuesday.

• Since a dismal July 29 outing in Milwaukee, it's been smooth sailing for reliever Ryan Mattheus entering Sunday's series finale. The right-hander was roughed up in an eventual 11-10 victory over the Brewers, allowing four runs (all earned) on five hits, including three home runs, in 1 2/3 innings.

It's the only time this season he's allowed more than one home run in an outing, and it also set season highs for hits and runs allowed.

But since then, Mattheus has logged a spotless month of August. In 13 appearances this month, he has tossed 14 scoreless innings, allowing just two hits while striking out eight. He's recorded two holds and one win in that span. Opponents are hitting 2-for-40 against him.

• This weekend marks the Nationals' first road series loss since June 22-24 at Baltimore (1-2). Washington had been unbeaten in its last eight series away from Nationals Park (six wins, no losses, two splits).