CHICAGO - The Phillies were on the wrong end of a lopsided loss yesterday, so closer Jonathan Papelbon kept his coat on and stayed in his seat in the visiting bullpen at Wrigley Field.

The embattled closer's next save appearance will likely come this week at Citizens Bank Park. In his most recent appearance, a perfect ninth inning Saturday to record his first save of the season, Papelbon never threw a ball harder than 91 mph and saw nine of his 13 fastballs register at 90 or below on the ballpark radar gun.

Coming off a first week when Papelbon was OK in one outing, awful in another and lacking velocity in the third, general manager Ruben Amaro Jr. remains confident in his $50 million closer.

"Right now I am," Amaro said yesterday at Wrigley. "Until he proves that he can't [be effective] . . . If he keeps getting three outs, I'm happy."

Papelbon recorded three outs in succession with relative ease in Saturday's 2-0 win over the Cubs. But his dip in velocity was notable: Papelbon's first-pitch fastball to the third hitter of the inning, Emilio Bonifacio, clocked in at 88.

Two years ago, in his first season with the Phillies, Papelbon's velocity peaked at 95.24 in the final weekend of the season and was never lower than the 93.94 it averaged in April, according to PITCHf/x data. In three appearances this season, Papelbon's fastball is averaging 91.04.

Doing the easy math, that's nearly a 3 mph decline and, at times, as much as a 6 mph drop. Amaro admitted to being concerned with Papelbon's velocity drop last year and remains that way.

"I'm still concerned," Amaro said. "I mean, I'd like to have him throw harder, to have better stuff. But we'll throw him out there and hope he's effective using his different pitches. [All players] have ebbs and flows sometimes. We'll see."

Speaking to reporters following Saturday's game, Papelbon said he generally gets stronger with work throughout the season, peaking in June. He has a point, to a degree.

In 2011, Papelbon's average fastball registered at 94.61 in April and at 96.10 in June. In 2012, it went from an average of 93.94 in April to 94.36 in June and 95.08 in September.

But last season, Papelbon's average fastball was 92.99 in April, then down to 92.82 in June and down again to 91.71 in September. This spring, the closer admitted to pitching through a nagging hip injury last season.

So is Papelbon healthy?

"He hasn't had any complaints," Amaro said. "He hasn't complained about anything."