— used to suggest another possibility ▪ If we don't win today, there's always tomorrow. [=we might win tomorrow] — usually used after can or could ▪ If she doesn't answer the phone now, you can/could always try (calling) again later. ▪ If you don't have enough money now, you can always use your credit card.

The dictionary says that "always" is used to suggest another possibility, but I don't understand why it's necessary to use the word after "can." Why wouldn't it be enough to say "can," may I ask?
Of course you can just say 'can' , but you should have learned by now that languages have many ways of saying things, many habitual phrases, and many pseudo-synonyms, and that native speakers make use of them to add communicative value to the standard textbook sentences that learners too often study.

'Always' here is an intensifier for the possibility that is being suggested. It is often used as a note of encouragement or consolation for the person spoken to.
Thank you, Mister Micawber.

"Pseudo" means "not real or genuine," and "synonym" means "a word that has the same meaning as another word in the same language." What does "pseudo-synonym" mean?