repairing wet subfloor under ceramic tile

After 3 years in my new bathroom, a lot of water recently dripped on the floor near the tub. It has not gone on for a long time, perhaps 1 -2 weeks. The caulking must have deteriorated a bit and water got underneath one small tile 2 x4 inches, and partly under another tile, 4 x 12 inches so that the tiles (or part of a tile for the larger one) are squishy - the grout is slightly cracked. I probably can pull up the smallest tile - I am not sure if it is detached from the wet plywood or whether the attachment is still good but the plywood is just soft. I was thinking of taking up the one small tile, and letting the area dry out - perhaps using blow drier or light bulb to do this. If the wood gets hard I would cement it down and regrout. I am trying to avoid lifting the second tile and wonder if the drying out will help the adjacent tiles somewhat. ALso wondering if I need to put something on the plywood before putting tile back to give it strength, if it should not return to normal. it might be a real project to try to cut out the small plywood subfloor area but perhaps there is no other way. There is a second subfloor below this new 1/2 inch plywood.
thanks for any guidance. I have done ceramic tile over cement floors but had a professional do this installation. I might have a few extra tiles if one breaks during removal but I am trying not to make the project into a big one
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