When National Football League “experts” said Tim Tebow could not cut it as an NFL quarterback, and Major League Baseball “experts” claimed the steroid era was over, these analysts created enough hot air to carry a big balloon “Around the World In Eighty Days.”

Tebow has not only made it as the Denver Broncos’ starting quarterback, he has done it with a combination of fourth-quarter rescue skills we used to see from Joe Montana combined with a touch of Houdini.

In a potentially shocking fall from grace, Ryan Braun, one of MLB’s most respected and popular players as the Milwaukee Brewers’ left fielder, tested positive for performance enhancing drugs (PED) during the National League playoffs last October. Strongly protesting his innocence, Braun has appealed the 50-day suspension scheduled to take effect at the start of the 2012 season.

Braun was named the NL’s Most Valuable Player just four weeks ago.

The Tebow and Braun stories show that those overly exuberant talking heads should think before spewing out such empty verbiage.

Starting in 2007, when he became the first sophomore to win the Heisman Trophy as the nation’s best collegiate football player, Tebow was roundly criticized as a poor prospect for an NFL quarterback job. Maybe he would make a good receiver, a good running back or even a good defensive back. But Tebow would not be a good quarterback in the pros.

The reasoning was that the University of Florida southpaw was not accurate in his throwing, and that he threw passes off his back foot. He threw badly to his left when running to his right. And on and on. Tebow just would not make it.

But the whiz kid for the Gators accounted for 51 touchdowns in 2007 by throwing 29 TD passes and running for 22 touchdowns. This was Tebow’s scrambling style in an option offense not uncommon in college football but rare in the NFL.

The “experts” who said Tebow was not going to make it in the NFL as a quarterback were following what some of the NFL coaches and officials were expressing all during Tebow’s undergraduate career. He was going to have to undergo considerable testing before anyone would commit to drafting him.

But the Denver Broncos took the big guy in the first round of the 2010 draft, and are they ever glad they did.

The scrambling young man who publicly credits God and Jesus Christ with all of his success still throws a terrible pass most of the time. He has receivers who don’t catch as many of Tebow’s few good passes as they should. That may be simply that they are so surprised when a pass is accurate that it overwhelms them.

But somehow or other, this NFL sophomore, who is the hero of the mile-high country, has turned into “The Little Engine That Could.”

When Denver hit the bottom of the AFC West, coach John Fox replaced Kyle Orton with Tim Tebow as the starting quarterback. The youngster — scrambling, running, passing and praying — has led Denver to seven ­victories in his eight starts, taking the team from the cellar to the attic as the Broncos are now in first place by a game over the Oakland Raiders.

Tebow has engineered either a come-from-behind fourth quarter or an overtime victory six times in those eight games as the Broncos have become an option offense giving Tebow the chance to run or pass. He runs well and still does not pass well.

But he is winning.

The Broncos, whose strong defense gives Tebow a chance to rescue victory from the jaws of defeat, face the New England Patriots today in Denver. This is the toughest test to date for the quarterback, who is somewhat controversial because he is driven by strong religious convictions that he expresses very publicly and very often.

Just do not listen to those who claim Tebow won’t make it as an NFL quarterback.

As to Braun, the pundits may have had it all wrong with this apparently very likeable and excellent baseball player who just completed his fifth season with the Milwaukee Brewers, the team once owned by the current MLB Commissioner, Bud Selig.

Braun’s appeal on the PED positive test will probably be heard next month by a three-person panel consisting of a representative from the commissioner’s office, another person from the player’s union, and an unaffiliated arbitrator agreed upon by both sides.

Ever since MLB began its current program of drug testing in 2003, no player who tested positive for PED has won an appeal. Specialists in these testing procedures say that Braun faces a very difficult challenge to prove he is not guilty of violating MLB drug use rules.

And so it goes with recent hero-like athletes in MLB such as Alex Rodriguez, David Ortiz and the tempestuous Manny Ramirez. Each of these athletes has admitted to using PED or failed a drug test, as did Ramirez, who suffered a 50-day suspension.

But as recently as January 2010, Commissioner Bud Selig of MLB told The New York Times, “The use of steroids and amphetamines among today’s ­players has greatly subsided and is virtually nonexistent, as our testing results have shown. The so-called steroid era is clearly a thing of the past.”

Selig might have been whistling by the cemetery or else today’s players have come across ways to hide drug use that were not available to “juicers” in the past.

Whatever the problem, it seems clear that we should not be too gullible when it comes to hearing unabashed praises heaped upon do-good athletes who become so well-liked and popular in a community that they can do no wrong.

Certainly all Milwaukee Brewers fans are rooting for Braun to win his appeal. So am I. It is not fun to see an accomplished and otherwise decent young man fall this way.

Have we not seen once highly respected people in athletics fall off their pedestals recently? The Brewers signed Braun to a five-year extension of his contract last April that will carry him through 2020 at $105 million over those last five years.

Is a man worth that kind of money for hitting an average of 32 home runs a year and batting .332 so far in his five major league seasons if he did it on PED?

But Braun told the Milwaukee Sentinel ­newspaper a week ago, “I am completely innocent.”

If Braun loses his appeal and the 50-day suspension stands, the Brewers’ left fielder should not accept the NL MVP award.

When listening to talk of Tebow as a bad quarterback prospect and discussion of the end of the MLB steroid era, one might be wise to take it all with a grain of salt.

Gordon White served 43 years as a sports reporter for The New York Times. His email is sports@thepilot.com.