"I didn't say anything to the team yet," Manuel said. "You know what? I will say something to them. At the moment, I don't know what to say."
The Phillies' skid is the franchise's worst since the team lost 13 of 14 games Aug. 28-Sept. 14, 1999.
In front of 37,235 at Citizens Bank Park, the Phillies' offense sputtered again Sunday and mustered just four hits. The Phils have averaged 2.4 runs per game in their last 14 contests, and have been held to one or no runs in seven of their last 13 games.
A frustrated Manuel said he thinks his team needs to start having more "hunger" at the plate.
"I don't see no really 'getting after' those at-bats," Manuel said. "We look like we take it very casual. Like it's, 'We'll get 'em next time.' No, that's not good enough."
Manuel also said he felt the team has lacked focus at times in the last two weeks. Cliff Lee -- who pitched Sunday for the first time since July 21 -- thought the team needed to find a spark.
"We got to have more pride, we got to have more fire and play better fundamental baseball, period," Lee said. "If we do that, we'll turn it around."
Lee went five innings and gave up four runs (three earned) on 95 pitches. Lee had eight strikeouts, but got into jams in the first and fourth innings.
The lefty also got little help from his offense.
Carlos Ruiz had a double and scored in the third, but the Phillies had just three hits the rest of the way. It looked as though the team might get something going in the fifth when the first two runners reached base, but after two outs, John Mayberry Jr. got picked off of second base to end any semblance of a threat.
"That becomes inexcusable," Manuel said of Mayberry's gaffe. "When you're playing like we are now, you've got to really be concentrating on staying focused and playing the game right and cutting down and eliminating mistakes. But at the same time, too, the more that you see mistakes and the more you see somebody keep making mistakes over and over and over and over, that might tell you what kind of player that he is."
The Phillies were a game above .500 on July 19, but not much has gone right in the past two weeks. They are 16 1/2 games behind Atlanta in the National League East and 11 games under .500. Injuries to Ryan Howard, Ben Revere and Domonic Brown have decimated the lineup, and bench players like Mayberry have seen increased roles.
Manuel does not have all of his players healthy, but he expects the ones on the field to maintain a level of concentration.
"I feel like there's a situation on our team where we definitely get out-talented," Manuel said. "It doesn't give me any reason why you can't concentrate, stay focused on your at-bats and play the game right."
It was Alumni Weekend at Citizens Bank Park, and the 1993 National League champion Phillies were honored before Sunday's contest. There were various odes to great Phillies of the past since Thursday and many video tributes were played on the scoreboard.
But the current club lost its fifth straight series and was swept for the third time in four series.
Lee was the subject of trade rumors last week, but the Phillies did not make any moves. The All-Star is signed through 2015 and said he has to maintain the mindset that the club can become a winner again.
"I'm here, I'm going to be here for another couple of years, I got to stay positive," Lee said. "I got to hope that we win, and I got to expect that we win. I don't know what other way to look at it."
Stephen Pianovich is an associate reporter for MLB.com.