Zack Cozart (21% Ownership)
Cozart is one of those players that I think ultimately will be more valuable for real life teams than fantasy. Defensively he's very strong and he even led the league in Sacrifice Flies but there are plenty of holes offensively.
While he does have some use in fantasy for squeezing home runs out of the shortstop position (27 homers over the last two years) his rate stats range from uninspiring (.254 average) to atrocious (.284 obp).
His most similar player through age 27 is Clint Barmes. In his age 28 season, he only played 27 games due to injury. While he did go on to post double figure home runs in three seasons, he never posted an above average OPS+ but he's managed to stick around because his defense is good enough to keep him at least one win above replacement despite the fact that his offense is borderline non-existent. It's pretty likely that Cozart's career is headed down the same trajectory as Barmes.
Javier Baez (20% Ownership)
This speaks pretty highly of what people think of Baez that he's owned in 20% of leagues even though he's never played a single game above AA. If you are in a keeper league, Baez would definitely be worth picking up.
For non-keeper leagues, he's probably not worth picking up currently as its more than likely he'll at least be in AAA for a couple of months prevent super 2 status (er I mean to "work on his game"). Definitely keep an eye on when he ends up in the bigs, and in a best case scenario he could be one of those rookies that tilts the outcome of fantasy leagues everywhere.
It would also help to keep an eye on how he does the rest of spring. So far (small sample size alert), he's hit a couple homers in 12 at bats and has a 1.417 OPS. Base on the opponent quality metric that's now on baseball-reference, he's doing this against relatively strong competition.
All numbers, comparisons, etc. found on baseball-reference.com