Joe Morgan's Oakland Mansion for Sale

The Oakland mansion built by baseball legend Joe Morgan is up for sale -- again -- complete with a tennis court, sauna, game room ... and a CARPETED BATHTUB!

The 5,008 square foot home -- with 4 beds and 3.5 bathrooms -- was built back in 1980 ... and has hit the market for $2.8 million.

The property is massive ... and you can probably imagine the parties that went on in that place back in the day.