Have tickets for July 25th 1 PM game..
Did not think ahead about just purchasing parking space..
Now my usual online source only has 1/2 mile away available.
When I stay at airport I often take light rail downtown...noticed
stop "Safeco " field....
Does Light rail have "park and ride" parking?? I have noticed
parking lot at Tukwila. Don't know rules for use??
Then again there is "parking" at airport for people flying in or out...Any ideas how to use this option..?
I know all this may sound weird...But 30 years SFGiants
fan...now living in Eastern WA and really want to enjoy the game with friends.

Where are you staying?

There's free parking at the Angle Lake station, at present the southern terminus of the light rail route, around a mile or so south of the airport station. https://goo.gl/maps/bjD4jdr8Yn32

You can also park ($4 per hour I think) in the Seatac airport parking garage, which is connected to the light rail station by a skybridge.

The Stadium train station is roughly a 5 minute walk from the ballpark entrance.

Century Link and Safeco field both have huge parking lots/parking garages. Are you sure there's no space there? Or at any garage or lot anywhere in Pioneer Square?

We have season tickets and always park right there at the garage across from Safeco field. We do not buy the parking pass with our tickets as we only drive to the ballfield part of the time, the rest of the time we take the bus or Uber/Lyft. So when we do park by Safeco, we do not have any special privileges and we have never had an issue there finding a spot.