Petersen -- hitting .212 with 9 runs and 2 RBIs in 52 at-bats -- was demoted so that Miami could reinstate Austin Kearns who had been out since May 22 with a hamstring injury. Kearns is currently hitting .339 with 3 homers and 9 RBIs.
While Petersen was sent down in order to reactivate a player from the disabled list, Murphy's demotion was solely based on performance. Murphy -- has appeared in 25 games including eight starts at second base -- was just 6-for-45 (.133 average) at-the-plate though four of his hits were for extra bases (two homers and two doubles). The Marlins recalled first basemen Gaby Sanchez on June 10.
Miami has made more than 25 roster moves so far in 2012 and many more are expected. The Marlins will have to make another move when outfielder Emilio Bonifacio returns from his thumb injury -- possibly by the end of June.
The rest of the article will look at who Miami could demote next.
The former 2009 Rookie of the Year could have easily been selected for demotion instead of Peterson.
Coghlan -- already been demoted this season -- is hitting .151 (13-for-86) with 1 home run, and 10 RBIs. In addition, Coghlan has just two hits in his last 13 at-bats.
It is unlikely Buck will get demoted though not impossible. One thing for sure it is time to give Brett Hayes more at-bats.
Buck -- got a vote from Guillen on June 1 -- is hitting .162 with 4 home runs with 13 RBIs. Buck has also struck out 42 times and drawn 27 walks.
Defensively, Buck has committed five errors and thrown out just 9-of- 30 base stealers.
The 24-year old first baseman/outfielder -- was given a few days to clear his head after going through a 0-for-18 streak -- will need to pick it up offensively when he returns to the lineup on June 10.
Morrison -- now hitting .227 for the season -- went 3-for-4 with an RBI and a run scored versus Tampa Bay on June 10. Morrison hit .310 with 2 homers and 10 RBIs in April.
Morrison has also hit a total of 4 homers, drove in 15 runs and struck out 33 times in 2012. Morrison's 2012 on-base percentage (.315) and slugging percentage (.345) are well below his career average in both categories.
The 29-year old long reliever has eaten up innings for the Marlins when needed but he has also given up more than a run a game.
Gaudin -- pitched multiple innings in 8 of his 12 appearances -- is 1-0 with a 4.62 ERA. Gaudin has given up 29 hits, 13 runs and recorded 19 strikeouts in 25.1 innings. In addition, Gaudin has posted a .290 batting average against and a 1.46 WHIP.
After a successful season debut on June 9, the 26-year old was rocked by Tampa Bay on June 10.
Rosario -- didn't record an out on June 10 -- surrendered three runs on four hits. Rosario threw 1.2 shutout innings versus the Rays on June 9.
For the season, Rosario is 0-0 with a 16.20 ERA. Rosario also has a .444 batting average against and a 2.40 WHIP.
Daniel Benjamin has followed the Marlins since the team's inception in 1993.