Today, Freeman has the better matchup with an OPS of 1.411 against Quantrill (18 plate appearances). That's compared to Olson's OPS of 1.158 versus Singer (9 PA). That's a pretty big difference, highly consider going with Freeman.
Weather impact
Heavy wind (blowing out), hot temps, ballpark elevation, etc can all have a big impact on long fly balls. An extra few feet can be the difference between warning track and a 3-run dinger. In Freeman's game, our HRForce Index at first pitch is 1.2 (20% more HRs expected). Meanwhile, Olson will be playing under an HRForce of 1.2 (20% more HRs expected). With equal HRForce values, ball flight conditions are roughly the same in both games. So, weather's a draw.
Weekly Roster Lock Leagues
For those of you in leagues that require you to set your lineup before the start of each week, day offs can be a bummer. Everything else being equal, give the edge to players that play at least one more game a week. For the M-F week that includes 9/27/24, Freeman has 6 games scheduled, while Olson has 5. So, with one more game, that could make a difference, especially in H2H leagues where you need to pile up points. Slight advantage to Freeman.