Ozuna entered the season as Miami's No. 2 prospect according to Baseball America, after hitting .310/.375/.585 in the second half of 2011 as a 20 year old in Low A. Ozuna hit .266/.328/.476 in 489 at bats with 24 home runs for Jupiter, Miami's A+ affiliate.
Skipworth, Miami's first round selection in the 2008 First-Year Player Draft, has been a disappointment in his minor league career. In his second full season in AA in 2012, Skipworth hit just .217/.285/.414, drawing just 36 walks while striking out 143 times in 420 at bats. Skipworth, though, did slug 21 home runs.
Skipworth was ranked as Miami's No. 21 prospect by Baseball America coming into 2012.
Jensen, selected by the Marlins in the 12th round of the 2010 First-Year Player Draft, hit just .234/.338/.452 in 445 at bats as a 24 year old in AA. Jensen did play well in the Arizona Fall League this year, hitting .330/.390/.593 in 91 at bats.
Olmos, the only pitcher added to the 40-man roster by the Marlins on Tuesday, spent most of the season in A+. The 22-year-old appeared in 24 games for Jupiter, starting 13, and was 1-5 with a 4.33 ERA. Olmos struck out 78 in 89-1/3 innings, while walking 48.