Rooney heads to Brazil with the weight of a nation on his shoulders once again but question marks remain on whether the Manchester United striker can produce the goods on the international stage, with him yet to score a World Cup goal in two previous appearances.
And while he has entered previous World Cups under an injury cloud, former England striker Shearer says it is time the 28-year-old finally delivers at football's showpiece event, where Roy Hodgson's men will come up against Italy, Uruguay and Costa Rica in Group D.
"It's a gap in the story of his career which he would like to fill," Shearer said. "But he probably hasn't yet gone to a World Cup in the best of fitness and you can't argue with his record at international level overall.
"But he needs to go out and have a big tournament. If he does that, he will be the key to us having a successful World Cup. When Rooney plays well, England play well."
Shearer added: "I'm a Rooney fan. He ticks all the boxes as a player, but for him to be put in the same bracket as Lionel Messi or Cristiano Ronaldo, he needs to have a great tournament in Brazil.
"Having said that, Messi has yet to set the place on fire at a World Cup as well."
The Newcastle great, however, has backed Rooney to surpass Sir Bobby Charlton as England's all-time leading goalscorer.
"Rooney has scored 38 goals for England," he said. "He's only 11 short of Bobby Charlton's record and I think he will go on to break it."
Rooney is also closing in on Charlton's record (249 goals) at Old Trafford, with the United star just 33 goals short of eclipsing the mark.
