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

8/27/2013 11:31 P.M. ET

Sandy: No update on a timetable for Harvey

NEW YORK -- While Matt Harvey tweeted Tuesday that he'll be back April 1 of next season, Mets general manager Sandy Alderson said there is no update on a timetable for Harvey's return.

"If that's his tweet, that's his tweet," Alderson said.

An MRI revealed Monday that Harvey has a partial tear in the ulnar collateral ligament in his right elbow. It'll almost certainly keep the hard-throwing phenom out for the rest of this season. If he and the team decide he should undergo Tommy John surgery, Harvey could miss the 2014 season also. Harvey was officially placed on the disabled list Tuesday.

That's why Harvey's tweet Tuesday was so surprising. But Alderson said the team hasn't learned any new information regarding Harvey's injury.

Mets call up den Dekker, will play him some in center

NEW YORK -- When the Mets traded Marlon Byrd to Pittsburgh along with John Buck, it opened up an opportunity for Matt den Dekker. New York selected the 26-year-old's contract from Triple-A Las Vegas on Tuesday, giving the Mets a chance to see a player who they hope could be a part of their future.

After breaking his wrist in Spring Training, den Dekker played 53 games for Las Vegas. He hit .296 with six home runs and 38 RBIs. He had a .486 slugging percentage and a .366 on-base percentage.

"It's hard to describe how that feels, first time getting called up," den Dekker said. "But it felt really good, and I'm just glad to be here."

Den Dekker said Las Vegas manager Wally Backman called him, pitcher Robert Carson and catcher Anthony Recker into his office Monday and told them there was a possibility they were going to join the Mets. Backman told the three of them to go to the airport on Monday where they'd have plane tickets waiting for them, but they still weren't sure if they'd be heading to New York.

Then they were told to get on the plane, and den Dekker said they found out about what happened when they landed in New York at about 5 p.m. ET.

Mets manager Terry Collins said den Dekker will see some time in center field through the end of the season. While Juan Lagares has given the Mets stellar defensive play in center, the team wants to see how den Dekker performs in that role in the Major Leagues.

"Juan's played great, and I will never, ever say anything different," Collins said. "Matt den Dekker is going to play some center field here."

The other option to fill Byrd's void in right field is to employ a platoon of the left-handed-hitting den Dekker and the right-handed-hitting Andrew Brown.

Collins said that's probably what the team's going to do for now, but "that doesn't mean Matt's not playing center."

Trying to replace Byrd's bat in the lineup isn't going to be easy to do. Byrd was hitting .285 with 21 home runs and 71 RBIs.

But general manager Sandy Alderson said having an opportunity to open playing time for other players is one of the benefits of the deal.

"Obviously, the downside is we give up someone like Marlon who's performed very well," Alderson said. "But this does give us an opportunity to see some other people."

Collins not thinking about uncertain future with Mets

NEW YORK -- Terry Collins doesn't have a contract for next season. He's still being evaluated before the team determines whether or not he'll be brought back as the manager of the Mets. With Tuesday's trade, Collins lost his most productive hitter, Marlon Byrd. He also lost John Buck, a catcher who brought a veteran presence to the clubhouse.

Collins has a roster dotted with young players who have spent time in the Minor Leagues this season. How the team fares in the final month of the season is included in the evaluation process, though it's not the final or only factor.

"I have said before and reiterate that how Terry's evaluated is beyond simply wins or losses," general manager Sandy Alderson said. "It's perceived that this will make it more difficult for him to win. I don't necessarily hold to that belief. Obviously, all the circumstances will be taken into account."

All season long, Collins has worked with a young team. With Monday's revelation that Matt Harvey has a partial tear in the ulnar collateral ligament in his right elbow and then Tuesday's trade, Collins now has to lead the Mets through adversity.

But Collins isn't thinking about his own future at this point.

"I will reiterate the same things I've been saying all summer -- this is not about me," Collins said. "This is not about me, this will never be about me. This is only about our team in that clubhouse and those 25 guys that have got to go out and play every night."

Instead of considering his own contract status, Collins said his concern is making sure his players know they're going to need to fulfill certain expectations.

He might not have a contract for 2014, but Collins certainly has his work cut out for him through the end of this season.

"My job right now is to make sure they understand what's expected of each and every one of those guys," Collins said, "and they go out and attain that."

Mets sending five players to Arizona Fall League

NEW YORK -- Five Mets prospects are heading to the Arizona Fall League to continue their development.

The Mets are sending pitchers Chasen Bradford and Hansel Robles; catcher Cam Maron; infielder Aderlin Rodriguez; and outfielder Cory Vaughn to Arizona. All will be playing for the Scottsdale Scorpions, which comprises players from the Braves, Giants, Pirates and Yankees in addition to the Mets.

The league, which includes six teams, begins play on Oct. 8. Each team has a roster of 35 players.

Robles is the highest rated prospect the Mets are sending. The 23-year-old right-hander is ranked No. 20 on MLB.com's list of the Mets' Top 20 Prospects.

He's spent this season with the Gulf Coast League Mets and Class A St. Lucie, where he's currently 5-4 with a 3.99 ERA in 15 games, 14 of them starts.

Bradford, 24, is currently pitching for Double-A Binghamton and has a 3-1 record and 0.42 ERA in 17 relief appearances. He has allowed 15 hits in 21 2/3 innings. Bradford began the season with St. Lucie, where he was 6-2 with a 3.71 ERA.

The Mets drafted Bradford in the 35th round of the 2011 First-Year Player Draft out of the University of Central Florida.

Vaughn, 24, has played with the GCL Mets, St. Lucie and Binghamton this season. In 65 Double-A games, he's hitting .277 with nine home runs and 49 RBIs. The Mets drafted Vaughn in the fourth round of the 2010 Draft. The Phillies drafted him in the 43rd round in 2007, but he decided to attend San Diego State.

Maron, 22, has spent all of this season with St. Lucie. In 81 games, the catcher is hitting .230 with no home runs and 28 RBIs over 81 games. He has a .325 on-base percentage. Maron was drafted in the 34th round of the 2009 Draft out of Hicksville (N.Y.) High School.

Rodriguez, 21, has played in 62 games with St. Lucie this season. He's hitting .260 with nine home runs and 41 RBIs.

Worth noting

David Wright, who's been on the disabled list since Aug. 3 with a strained right hamstring, is heading to Port St. Lucie, Fla., on Thursday to continue rehabbing his injury. Mets manager Terry Collins said Wright will first track pitches but won't swing since he's not ready to swing "100 percent" yet. Then the team hopes Wright can play in games by Sunday or Monday, Collins said.

• The Mets called up catcher Anthony Recker from Triple-A Las Vegas to fill Buck's spot on the roster. Recker spent most of this season with the Mets before they optioned him on Aug. 20. In 38 games with New York, he hit .193 with five home runs and 16 RBIs. Recker played in five games with Las Vegas and was 4-for-10 with a home run and four RBIs.

New York also recalled pitcher Robert Carson from Las Vegas. He was on the Mets' roster from April 21-June 10. During that stint, Carson had an 8.50 ERA in 13 appearances. In 42 games with Las Vegas, he was 3-3 with a 4.15 ERA and 11 saves.

Chris Iseman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.