Here are three players with low ownership rates who could pay immediate dividends in fantasy leagues:
Brett Cecil, Toronto Blue Jays (owned in 1% of Yahoo! leagues)
In a bit of a surprise, the Blue Jays started Cecil in the minors after he posted a decent rookie season in 2009. But he got the call to the majors after going 2-0 with a 2.45 ERA in two games in the Pacific Coast League. Cecil replaced Brian Tallet in the rotation and had a strong first start. He gave up two runs in six innings in Tampa Bay before allowing a two-run HR to Gabe Kapler in the seventh. Cecil has the chance to post good strikeout numbers and a league-average ERA if he can do a better job of keeping the ball in the park. In 100 IP in the majors, Cecil has a 6.93 K/9 and a 15.1 HR/FB rate.
David Freese, St. Louis Cardinals (owned in 5% of Yahoo! leagues)
In four seasons in the minors, Freese hit for both AVG and power. So far this season with the Cardinals, Freese has a .300 AVG but no home runs. He has an unsustainable .417 BABIP but he also has been having some issue with strikeouts, carrying a 30.0 K%. If he can start hitting a few home runs and cut down some on the strikeouts, he could survive the inevitable BABIP drop. Updated ZiPS projects him to finish with a .273 AVG and 11 HR, which is nice production off the waiver wire for third base.
Carlos Villanueva, Milwaukee Brewers (owned in 9% of Yahoo! leagues)
Always a good strikeout pitcher, Villanueva has 14 strikeouts in 10 IP so far this season. The rest of his early numbers are nearly as impressive, as he finally seems to have found a home as a reliever after bouncing back and forth between the rotation and the bullpen the past four years in Milwaukee. Villanueva has pitched in the eighth inning in three of his last four appearances. Perhaps this is the year that 42-year old Trevor Hoffman finally gives out, as his early season numbers are not confidence-inspiring. Villanueva would have to be under consideration along with Todd Coffey and LaTroy Hawkins as potential replacements. Hawkins has never really succeeded in multiple shots as a closer and Coffey has pitched in the eighth or ninth inning just three times in 10 outings this year, and all three of those were in mop-up roles. Add Villanueva for his fine pitching in middle relief and consider him a darkhorse candidate for saves.