In-season or off-season lifting?

After my freshman year in college baseball, I am not in a league this summer so I can focus solely on retooling my mechanics. I am planning on throwing two bullpens a week plus 2 or 3 more days a week throwing and/or a bit of long toss. I have from now until late August when fall baseball starts. Would you recommend me lifting on an off-season schedule to build more functional strength or an in-season schedule for the summer so I can be more fresh for my throwing and drills?

Also, what is the difference between in- and off-season lifting other than less in quantity? Is it the reps or sets? Should you not try to progress towards higher weights?

It is the off-season, isn’t it? Should probably lift according to an off-season lifting program.

Difference is that total volume goes down in-season and you should seek to maintain strength (assuming you are reasonably strong).

You should be trying to build explosive strength in the off-season, and trying to maintain or progress that power during the regular season.

I agree with Kyle and Nathan