The players identified in the preview are:
Packy Dillon - Catcher
Joe Blong - Pitcher
Zack Mulhall - Second Base
Dany Morgan - Left Field/Pitcher
Johnny McSorly - Third Base
Billy Redmon - Short Stop
Charlie Hautz - First Base
Shields - Center Field/Second Base
Arthur Croft (no position listed)
Shields was a teammate of 'the majority of them' at Notre Dame previously. Zack Mulhall was a member of the club in 1874. Neither of these two appeared with the Red Stockings in an offial league game during the season. A roster published in the Daily Journal of Commerce (Kansas City, MO) on March 28, 1875 still included Mulhall, but Tom Oran was listed at center field in place of Shields. An article in the St. Louis Republican on April 4, 1875 refutes a rumor that Mulhall was joining Washington, but implies he had not yet signed with the Reds either. Mulhall would end up appearing in two non-Championship games with the Reds, one at the very start of their pre-season, and the other as the tenth man in a "Ten man, ten inning" exhibition against the Keokuk Westerns.
On April 11, the St. Louis Republican indicated the roster was "definitively fixed" with Dillon, Morgan, Redmon, Blong, McSorly, Houtz, Croft, Oran and Charles Sweasy, with John Dillon as the tenth man. This is the club that started the season in the first game againt the St. Louis Browns.