The game on March 24 was cancelled due to rain, so 'Opening Day' for the season was March 25, 1888. The race between Latham and Johnson was also cancelled, as the grounds had been soaked by 36 hours of rain. Still, about 1000 fans showed up for the game, so a game was played. The Browns won 8-0, behind the pitching of Knouff and Sommers. Staley and Nyce pitched for the Whites. Using two pitchers in a game was a novelty at the time. The two clubs agreed to do this so that their pitchers (and catchers too) could get more work. The two clubs played three more games on March 27, 28 and 29 with the same arrangement. The Whites used Staley and Nyce in all four, while the Browns used Knouff and Somers in the first three, and Devlin, Somers and Ashland in the last. ('Ashland' was actually Joe Murphy, sportswriter for the Globe Democrat and former major league pitcher with a handful of games over the previous two seasons.) In all, the Browns and Whites played seven games during the spring, and the Browns won all of them.
After the initial series against the Browns, the Whites spent the next two weeks in St. Louis training while the Browns went on a trip to Memphis and New Orleans. They played a couple of game against locals clubs (winning both), but were mostly unable to find clubs that would play them. The Whites then played the first game of a three games series in Kansas City against the American Association club there on April 12, 1888. The remaining two games were cancelled after that club was able to reach an agreement with the Kansas City club in the Western Association for a short series instead, so the Whites returned to St. Louis, where they played one more game against the Browns. The Browns opened their season at home on April 18, so the Whites embarked on a road trip through Illinois and Iowa starting on April 16. They played 11 games in five cities - Bloomington (3), Peoria (2), Davenport (2), Rockford (2) and Dubuque (2). Outside of the games against the Browns, the Whites were pretty successful, losing only two times in their other spring training games. One of those was to the Kansas City club, while the other was a five inning game against Dubuque at the tail end of their road trip right before the season started. They finished the preseason with a record of 11-9.
The Browns set up several preseason series - with Indianapolis, Detroit and Chicago - as well as scheduling games against Memphis and New Orleans. The series against Indianapolis, billed as a matchup of the Browns and the 'old St. Louis Maroons' (the Maroons having moved to Indianapolis after the 1886 season) was to be in St. Louis at the end of March. These games were cancelled due to the high probability of bad weather, so that Indianapolis wouldn't have to risk the expense of a trip with no games played. The Browns played several more games against the Whites instead. The games against Detroit (the 1887 NL Champions) were billed by Von der Ahe as a redo of the World Championship series of 1887, which saw the Wolverines beat the Browns 10 games to 5 in a series of 15 games played in 12 cities over 16 days (including a double header with a morning game in Washington DC and an afternoon game in Baltimore). The Browns had gone into the series as favorites, having won 95 games during the regular season. Von der Ahe felt that the club hadn't played its best ball against Detroit (they hadn't), and he wanted a rematch. The first two games of the spring series were played in New Orleans, one game was played in Memphis, and the final two were played in St. Louis. The Browns won all five games, and Von der Ahe tried unsuccessfully to market the Browns as the new World Champions. A three game series was played between the Browns and Chicago in St. Louis, which the Colts won two games to the Browns one.