Saints captain Lallana was handed his international debut earlier this season, impressing in friendly matches against Chile and Germany at Wembley, prompting manager Roy Hodgson to describe him as a “major find”.
Since making his England bow last November, the midfielder’s form with his club has been scintillating.
And Paine, right, reckons it would be a travesty if he is not in the final squad for the World Cup.
“He’s an absolute certainty to go,” said Saints’ honorary president. “I would be so surprised if he isn’t picked.
“He ranks right the way up there, in terms of creative midfielders that England have.
“He’s natural, he floats over the ground, he’s reasonably quick, and he looks likely to score.
“I don’t see many in midfield who look likely to do that, except perhaps (Alex) Oxlade-Chamberlain.”
Paine also believes that 18-year-old left-back Shaw should be given the chance to prove himself in next month’s home friendly against Denmark – the last match before the provisional squad is announced.
“I still think he can make it,” said Saints’ all-time record appearance holder. “He would certainly be one that I would be looking at. For me, he has to be in the running.
“I would certainly be calling him up for the friendly before the World Cup. He’s as good as, if not better than, what we’ve got at left-back.”
Paine, who is also confident that Rickie Lambert remains in a strong position to make the squad, reckons there is a good chance that Saints could send three players to the World Cup.
“If we took three, it wouldn’t surprise me,” he said. “I’m not saying it’s going to happen, but it wouldn’t surprise me.
“Looking at their form, and the positions they all play, I just see that being possible.”
The Saints legend also believes that, despite a disappointing debut against Chile, in-form Jay Rodriguez’s outstanding club form has kept his hopes alive.
“I was disappointed with him when he played (against Chile), if I’m honest,” said Paine, who also believes that Nathaniel Clyne, and even fellow right-back Calum Chambers, are not far away from the senior team.
“He certainly didn’t play with the freedom that he does for Southampton, but maybe that was down to orders – I don’t know.
“I just felt he didn’t do his chances any good on that one performance, but if you’re talking about league form then he’s as good as anybody.
“He will again be in the thoughts, but maybe he’s not got quite as strong a case as the others do.
“He’s done brilliantly, though, to put himself back in Roy’s thoughts.”