Danny Santana and Kennys Vargas were both in Minnesota's Opening Day lineup this year, batting leadoff and fifth. Following impressive rookie campaigns, both were viewed as important young staples for the rebuilding Twins. Now, nearing the end of tumultuous sophomore seasons, both return from the minors as September call-ups, needing to prove that there's still a place for them in the team's plans. Regression was widely expected for Santana and Vargas in light of some ominous statistical indicators that came along with their overall outstanding production in 2014 – namely a lack of plate discipline exhibited by each. Yet, few could have anticipated that the dropoff in both cases would be so dramatic. Vargas was demoted twice, first to Triple-A and then to Double-A. Santana was given an extremely (some might say overly) long leash and still couldn't do anything to justify his place in the lineup. He was optioned at the end of July with a miserable .541 OPS and 16 errors at shortstop. Now, both players return to the fold as September call-ups, and with some momentum behind them. Vargas has shown tremendously improved patience at the plate since his latest demotion, drawing 42 walks against 52 strikeouts in 56 games between Double-A and Triple-A while hitting .277/.418/.492. Santana ended the month of August on a blistering tear at Rochester, with six straight multi-hit games and a .403 batting average in his last 15 contests. Despite their fine work in the minors, neither player is going to be in line for regular playing time this month, and maybe not even a substantial role. Eduardo Escobar has excelled at short since Santana's removal, hitting .295/.375/.577 in August with much sharper defense and surprisingly strong plate discipline (14 strikeouts and 10 walks in 88 plate appearances). At this point the Twins need to be planning around Escobar as their shortstop. Santana can help out this month as a pinch-runner and bench guy, but I think his opportunity is gone. For Vargas, there appears to be a bit more hope. For one thing, his improvement in the minors was more encouraging in that he clearly improved his approach, as opposed to Santana whose 15-game torrid stretch came attached to a 12-to-0 K/BB ratio. Obviously Miguel Sano is entrenched at DH for the time being but long-term the Twins would like to find a place in the field for him. If Vargas can demonstrate the same adjustments that he made in the minors when he gets his chances, he can re-establish himself as a legit DH option going forward, although I don't think there's anything he can do at this point to ensure himself a spot on next year's Opening Day roster. Ultimately both players are going to have their work cut out for them this month, because they've dug themselves pretty deep holes and their sporadic playing time will make it tougher to maintain the grooves they've found in the minors. The Twins have put themselves in position to contend for a postseason berth without getting much of anything from two players that were viewed as key cogs at the outset of the season. Now both will have a chance to contribute to a contending team – albeit in significantly reduced roles. Can Vargas and/or Santana end a negative season on a positive note?