Is this combination of words, which I hear all to frequently, 'could potentially', redundant?

We could potentially lose this game.

I feel 'could' expresses the doubt/the conditional aspect of the sentence without needing potentially

Yes, strictly speaking. It is used to bolster the sense of unlikelihood.
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Ah, I suppose you could say that. It does seem to 'bolster,' but I've always been afraid to use it.
I agree with you. 'Could' and 'potentially' mean the same thing. Only one is needed.

p.s. 'all to frequently'???!!
Yes, the two words when used together are redundant.
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Yes it's a redundancy. Could means is potentially. Potentially is an adverb originating from potere (Latin), which is the verb ''to be able (to)''. It is extremely overused in the UK, and another example of people trying to sound cleverer than they are, and they generally use it a lot. The same type of people who use literally incorrectly, and overly so.

There is no potere in Latin. The infinitive is posse. The stem is pot.