This Miami Marlins ace was seen as the best fit for the Chicago Cubs' starting rotation, but he may not be available at the trade deadline.

There’s rightfully no focus on improving the Cubs lineup. Entering play on June 14, Chicago had the second-most runs scored (380) with the fourth-best batting average (.256) and slugging percentage (.439). Pitching is an area for improvement, though, especially since another high-end pitcher could join the postseason rotation.

With the deadline on July 31, here's which front offices could make -- or break -- their future this trade season.