(Reuters) - San Francisco 49ers head coach Jim Harbaugh said on Tuesday he wished he could change his play-calling at the end of Sunday's 34-31 Super Bowl loss to the Baltimore Ravens.

Despite marching down the field, the 49ers failed to score on the final three plays before the Ravens punter took a safety with four seconds left. The clock ran out on the ensuing kick.

"We came up five yards short. Certainly, knowing how it ended up, how it finished when we didn't get the ball in, yeah, we would have liked to try a different play call," Harbaugh told a news conference at the 49ers complex after the team's return from New Orleans.

"When you do something that doesn't work, you would have liked to have done something different — at least tried it. But you can't."

The 49ers, down by 22 points in the third quarter, were on the verge of the greatest Super Bowl comeback but failed to score despite having a first-and-goal from the seven-yard line in the final minutes of the title game.

After a two-yard rushing gain on first down put the ball on the five-yard line, the NFC champions tried three times to pass the ball to receiver Michael Crabtree, who was closely guarded and failed to make a reception for the go-ahead score.

The final plays came under criticism from disappointed San Francisco supporters, who wondered why the 49ers had not tried to give the ball to running back Frank Gore, who had taken the ball to the seven on a 33-yard run to set up the scoring chance.

Or why they did not look for rangy wide receiver Randy Moss, who has long been adept on snaring touchdown passes in his long, illustrious career.

Or why San Francisco quarterback Colin Kaepernick did not try to run an option play, since he had earlier scored on a 15-yard scamper.

Kaepernick said on Tuesday that he changed the play-call at the line of scrimmage when he noticed the Ravens would be blitzing and playing man-to-man coverage on the receivers.

"I audibled to a fade to Crab," Kaepernick said. "I'll take Crabtree one-on-one with anybody."

Harbaugh said that in hindsight he wished he had tried something else, but that it was always easy to second guess.

"The would've-could've-should've is undefeated," he said. "That's never failed."