PHILADELPHIA -- One day after an MRI eased whatever fears Daniel Murphy had regarding his sore right shoulder, Murphy was in Tuesday's lineup, batting second and playing second base for the Mets.

Murphy said he felt no discomfort prior to the game, two days after tweaking his shoulder while swinging the bat. An MRI on Monday came up negative, leading the second baseman to treat his shoulder with nothing more than anti-inflammatory medication.

Murphy, who has appeared in 124 of the Mets' 129 games, described the news as "a relief."

"But it just confirmed what I thought," he said. "I didn't think there was anything wrong with me. I'm excited that I'm healthy, but it's pretty much what I thought it was going to be."

Of greater issue to the Mets was the fact that Murphy entered Tuesday's series opener against the Phillies mired in a 4-for-44 slump, with no extra-base hits and just two walks over that span. It is his second major slump of the season, following an 8-for-61 stretch that consumed most of his month of June.

"Never in my wildest imagination did I ever think Daniel Murphy would [slump that badly], with as good a hitter as he is and as good a swing as he's got, the way he uses the field to hit," manager Terry Collins said. "It just tells you what a strange game this can be."

Murphy's batting average is down to .283, after peaking at .336 on May 15. Because Murphy is not a power hitter, batting average tends to be a more telling statistic for him than for others.

"I still say at the end of the year, we're going to look up and he's going to be hitting .305," Collins said. "So he's got a hot streak coming."

McHugh to highlight callups, get the start Monday

PHILADELPHIA -- Collin McHugh's return to the starting rotation will highlight a modest group of September callups for the Mets.

McHugh, whom the Mets sent back to the Minors after his brilliant Major League debut last week, will slot back into the rotation on Sept. 3 in St. Louis. But he may not necessarily remain there for the rest of the season. Though manager Terry Collins was mostly mum Tuesday on the subject of callups, he said earlier this month that Jenrry Mejia should receive a start or two down the stretch.

The Mets figure to spend the rest of their callups on players who can fill holes in their roster. Jeurys Familia and Elvin Ramirez could slot into bullpen roles, and Mike Nickeas should reprise his role on the team's catching staff. The team will also recall Jordany Valdespin, who has spent much of this season with the Mets.

Not all of those players will be in uniform on Sept. 1, with Triple-A Buffalo's season stretching until Sept. 3. But they will come eventually.

"It's always exciting to see young players come up in September," Collins said. "But it also depends on what kind of opportunities they're going to get. I've seen a lot of guys get called up and just not play much. So we'll have to wait to see who those guys are going to be and how we're going to use them, and what roles they're going to be in."

The one callup assured of a significant role is McHugh, who struck out nine over seven scoreless innings in his debut. McHugh's presence should allow the Mets to stretch back out to a six-man rotation, giving Chris Young, Matt Harvey and Jon Niese extra rest down the stretch. Harvey, on a strict innings limit, may not make it to the end of the season without an extra day between starts.