© 2013 MLB Advanced Media, L.P. All rights reserved.

04/24/2013 7:19 PM ET

Edgin working his way through early struggles

NEW YORK -- After an encouraging start to the season, reliever Josh Edgin struggled yet again on Tuesday, leaving manager Terry Collins concerned about the young left-hander's confidence.

Edgin, 26, conceded two runs off four hits while recording just one out, marking his fourth straight appearance in which he's allowed at least one run. Though he started the season with four consecutive scoreless outings, he enters play on Wednesday with a 10.80 ERA after allowing nine earned runs in 2 2/3 innings over his last four games.

"You're always worried about a young player's confidence at this level when they're struggling," Collins said. "And to be honest, this is the first time, probably, Josh has really faced down time in his real brief career, where he hasn't been able to get guys out as easy as he has in the past. But you know what? You've got to learn how to rise above it."

A 30th-round Draft pick in 2010, Edgin compiled 75 appearances last season between the Minors and New York. He posted a 1.42 ERA at Double-A Binghamton in just six relief appearances before being promoted to Triple-A Buffalo, where he went 3-2 with a 3.89 ERA in 35 outings. He then pitched 34 games for the Mets, tallying a 4.56 ERA over 25 2/3 innings.

"We were in a situation where Josh got here fast," Collins said. "I'm a true believer in facing challenges and challenging young players. They need to learn how to fail, and they need to learn how to fail in the Minor Leagues, because when they get here, the failure has to be very short.

"He's struggling right now, [but] he's a tough kid. ... He'll get through this."

Despite swollen leg, Niese to make next start

NEW YORK -- One day after X-rays taken of his lower right leg came back negative, left-hander Jon Niese had some swelling and tightness in the area but fully expects to make his next start.

Niese, struck in the leg by a Mark Ellis comebacker on Tuesday night, plans to push back his post-start cardio workouts by a day and may also push back his bullpen session one day as well. Either way, he plans to take the mound on Sunday afternoon against the Phillies at Citi Field.

"I certainly didn't want him to go out with a sore lower leg, then all of a sudden mess up his shoulder or something," manager Terry Collins. "So if he needs an extra day, that's no big deal."

Given Niese's initial reaction -- hopping into foul territory before sitting on the ground for several moments without even attempting to stand -- things certainly could have turned out worse.

Including Tuesday's abbreviated start, Niese is 2-1 with a 3.81 ERA through five outings.

Marcum feeling confident as season debut nears

NEW YORK -- Once he was back on a mound throwing baseballs again, right-hander Shaun Marcum finally felt normal.

"I kind of took it slow those first couple of days when I got back down to Florida," said Marcum, who spent the past three weeks recovering from nerve inflammation in his neck. "But after that, once I got back on the mound and was able to let the ball go and not feel anything, my confidence shot through the roof. I'm not really worried about it at all right now."

The Mets will officially activate Marcum in time to make his season debut on Saturday against the Phillies following a nearly monthlong stint on the disabled list. He reported to Citi Field on Wednesday and said his "legs, conditioning, all that's underneath me," and expects to throw up to 95 pitches on Saturday.

"It's just a matter of going out there and trying to make these guys put the ball in play early in the count," Marcum said, "and try to get as deep into the game as I can."

Marcum, who posted a 7-4 record and 3.70 ERA in 21 starts for the Brewers last season, is coming off two scoreless outings in extended spring training spanning nine innings. He said it's difficult to gauge the quality of his pitches in those games because the hitters there tended to "swing at everything."

"I guess if the Phillies do that, I'll be OK," he said, laughing.

Bullpen limited for Wednesday's contest

NEW YORK -- With Jon Niese not expected to miss any time after leaving Tuesday night's game early with a leg injury, the biggest concern stemming from that early exit may be its effect on the bullpen on Wednesday.

Niese pitched just 2 1/3 innings before departing, leaving 6 2/3 frames to the bullpen. Five relievers combined to throw 138 pitches in the 7-2 loss, with left-hander Robert Carson tossing 38 pitches over 2 1/3 frames.

Manager Terry Collins plans to stay away from Carson on Wednesday, as well as righty Brandon Lyon, who threw 32 pitches in his one inning. Collins also needs to be careful with Jeurys Familia, who pitched 1 2/3 innings on Tuesday, leaving Josh Edgin, Scott Rice, Scott Atchison, LaTroy Hawkins and closer Bobby Parnell available.

"Our bullpen is in good shape," Collins said. "Edgin is still out there, Rice is fine, Bobby's fine, Hawk's out there and he's fine. We'll be OK, but if [starter Matt Harvey] takes one off his shin, we're going to have some issues."

Despite the remaining relief options, it doesn't hurt to have Harvey toeing the rubber on Wednesday. The right-hander has pitched at least seven innings in each of his first four outings on his way to compiling a 4-0 record and 0.93 ERA.

Collins, however, doesn't want Harvey placing any added pressure on himself after Niese's short start, and that's something pitching coach Dan Warthen will cover with Harvey during their pregame meeting.

"One of the things that's going to be brought up is, 'You've got to just be yourself. Go out and pitch, throw strikes, change speeds, do your thing, but don't try to do too much,'" Collins said. "Like I said, with his quality of stuff, if he's around the strike zone, he's going to be out there later in the game."

Anthony DiComo is a reporter for MLB.com. Follow him on Twitter @AnthonyDicomo. Paul Casella is a reporter for MLB.com. Follow him on Twitter @paul_casella. This story was not subject to the approval of Major League Baseball or its clubs.