As the Orioles prepare to begin spring training next week in Sarasota, Fla., and with it the next chapter of the franchise's rebuild under the leadership of executive vice president and general manager Mike Elias and manager Brandon Hyde, the focus will finally shift from the front office to the field.Without a major league free-agent signing and with many of the familiar faces of past years no longer with the Orioles, the cast of players who will be charged with starting the organization's transformation on the field is a unique one.This week, we'll break down by position groups who will be in camp, and who could factor in to the team's immediate plans, continuing today with the infield crew.Save for Chris Davis at first base, there's no other position with more players to get to know at spring training than the infield. Jonathan Villar made a favorable impression after the trade from the Milwaukee Brewers in July, but whether he plays at shortstop or second base, the rest of the middle infield cast will be fluid. Steve Wilkerson will be back in camp to fight for the utility role that he was meant to be in the mix for last year before his offseason banned-substance suspension, with a pair of waivers claims — Hanser Alberto and Jack Reinheimer — and Rule 5 draft picks Richie Martin and Drew Jackson representing new additions on the infield.Third base incumbent Renato Núñez will be part of an interesting group there that includes waiver claim Rio Ruiz, highly rated prospect Ryan Mountcastle, and Jace Peterson, who will be back as a minor league invite after re-signing as a free agent after his outright off the roster.Minor league free agents Christopher Bostick and Zach Vincej will round out the middle infield crew in camp, and can play all over the infield.The Orioles didn't offer Tim Beckham a contract because of an arbitration raise that would have made him too expensive for the production he offered, and he signed last month with the Seattle Mariners. Breyvic Valera, one of the five players who came back from the Los Angeles Dodgers in the Manny Machado trade, was designated for assignment and lost to the San Francisco Giants.Davis' status as the team's first baseman is unchallenged by virtue of his contract, and Villar will be a starter, whether it's at second base or shortstop. Likewise, Núñez made a favorable impression last year, though that was with an entirely different organization.After that, things are pretty fluid. Both of the Rule 5 picks, Martin and Jackson, would be making the jump from Double-A, even as they're both coming off breakout years in the minors for the Oakland Athletics and Dodgers, respectively. Their roster status that comes with their acquisition means that the team would have to keep them in the majors to keep them at all, so that would factor into things if they continue to show promise with the Orioles.That same roster consideration applies to Alberto, who was claimed off waivers from the New York Yankees but is out of minor league options. Those six could be the infielders the Orioles take north without much harm on the roster, with plenty of versatility to rotate players through different spots.Wilkerson, Ruiz and Reinheimer have minor league options remaining, so the Orioles could simply be in an asset-collection mindset.Wilkerson's speed and versatility could put him in a good position if one of the Rule 5 picks doesn't pop, though his options might not work in his favor. Likewise, the left-handed-hitting Ruiz could be an interesting platoon partner for Núñez, even if Núñez hit right-handed pitching better last year. Reinheimer found his stroke last year in Triple-A, but doesn't have the track record to elevate him above the rest of the new faces at this point. And Mountcastle could outhit everyone in this group in camp, but will need to make quite an impression defensively to factor into the major league roster situation.As for the non-roster invitees, they might find playing time hard to come by with so many rostered players requiring looks in the Grapefruit League.It might be a new era of Orioles baseball, but like so many springs before, there will be plenty of attention paid to the Rule 5 players, Martin and Jackson. With a good spring, either could grab a starting position on an Orioles team with nothing to lose. Any role they could have will dictate where Villar plays, too. Elias said at the winter meetings that he was the starting shortstop at that point, but that was before the Rule 5 picks.Villar will also be sneaky fun to watch in that he played with energy and abandon even at the end of a lost season, and it will be worth watching whether that continues. The Orioles will be the third team to try and harness all that talent and get the best of him for the long haul,. If he starts the year on the right foot and plays like he did down the stretch to begin 2019, he could develop into a valuable trade chip for Elias to use come July.Mountcastle will also be an interesting case to pay attention to this spring, as it will be the new coaching staff's first look at one of their most unique talents. His is the best bat in the club’s minor league system, but no one in the new regime is married to him being an infielder the way the last one was. If they don't see enough to keep him at third base, it could be a quick move elsewhere so they can get his bat to the big leagues quickly. He could also play freer there knowing that some of the most vocal doubters of his defense are gone.But anyone evaluating Mountcastle will quickly learn that any headaches caused by trying to figure out where he's going to play on defense are relieved some by watching him hit and realizing that the bat will be worth having around, no matter what.When Mountcastle enters games in the Grapefruit League, it could very well be in relief of Núñez, who holds a pretty significant distinction from the 2018 Orioles. He was a player who markedly improved as the season went on, and not a lot of players can say that. Another year of steady defensive improvement with a consistent bat could thrust Núñez into the conversation of players who will be in an Orioles uniform the next time the club is good, and that starts with a strong spring.