ST. PETERSBURG -- From the moment Wander Franco arrived at his first big league Spring Training camp, there were questions. Was the top prospect ready for the Majors? Could he possibly live up to the hype?

Those questions changed a few weeks after the 20-year-old shortstop’s unforgettable June 22 debut at Tropicana Field, and they kept coming all the way through his impressive postseason debut. Can he keep this up? Is he playing his way into American League Rookie of the Year votes? How would he handle the bright lights of the playoff stage? How is he doing this at his age, anyway?

The day after the Rays’ season ended with a loss to the Red Sox in Game 4 of the American League Division Series, manager Kevin Cash made us ponder another thought: Is Franco already one of the valuable players in all of baseball?

“I think you could make the argument that he's the most impactful player on any team in baseball,” Cash said Tuesday at Tropicana Field. “Certainly for us, our team was really good; we got better when he came. He lengthened our lineup. He made our defense better. He worked really hard on his defense to make his defense better, and it made our overall defense better.

“He is a game-changing player. It's going to be fun to watch for a long time.”

Consider what Franco has accomplished before his 21st birthday. He slashed .288/.347/.463 with seven homers, 18 doubles and five triples while only striking out 37 times over 308 plate appearances during 70 regular-season games. By Baseball-Reference’s calculation of Wins Above Replacement, he was the Rays’ fifth-most valuable player this season despite being called up in late June and missing more than a week in September due to a hamstring injury.

Franco had the fourth-highest bWAR of any AL or NL rookie this year. The list was led by teammate Randy Arozarena (4.2), the Reds’ Jonathan India (3.9) and the Rangers’ Adolis García (3.8), with Franco checking in at 3.5 WAR. One difference: The trio ranked above Franco played in more than twice as many games as he did. Arozarena had 141 games to accumulate his WAR total, India 150 and García 149.

Franco further solidified his status as a future superstar in his first taste of postseason baseball, going 7-for-19 with two doubles, two home runs, four RBIs and five runs scored during the Rays’ four-game ALDS loss to the Red Sox. The 20-year-old’s poise under the spotlight came as no surprise to Tampa Bay.

• No spotlight too bright for confident Wander

“I've been impressed with Wander from the day he got here,” Cash said before Game 4, when Franco hit a two-run homer at Fenway Park to help the Rays tie their elimination game. “He carries himself like a seven-, eight-year veteran player. He doesn't have seven, eight months in the big leagues.

“It's fortunate for us that we have him. It's a good feeling when he's walking up to the plate every night.”

Given his age and level of experience, Franco seemed to make history just about every time he walked up to the plate. His skills were on display throughout his historic 43-game on-base streak, tied with Hall of Famer Frank Robinson in 1956 for the longest in AL/NL history by a player 20 years old or younger.

Among the other Hall of Famers Franco passed while tying that record: Ken Griffey Jr., Al Kaline, Mel Ott, Arky Vaughan and Mickey Mantle. He made history in the playoffs, too.

• 'Typical Wander' bursts onto playoff stage

He became the fifth player age 20 or younger to homer in consecutive postseason games, joining Rafael Devers in 2017, Miguel Cabrera in 2003, Andruw Jones in 1996 and Mantle in 1952. The pair of postseason homers he hit before turning 21 also put him in elite company -- tied with Mantle and Devers behind only Cabrera (four), Juan Soto (three) and Jones (three). Cabrera is the only player with a longer postseason hitting streak at age 20 or younger.

Despite their frustratingly early exit, the Rays know they have a bright future ahead of them. They are loaded with club-controlled players and young talent, led by Franco, Arozarena and starters Shane McClanahan, Shane Baz and Drew Rasmussen.

“We thought it was going to be a special group coming in. They proved that,” Cash said. “I think there's a chance for us to be really, really good -- very confident we're going to be really good moving forward. And it's headlined by some very talented players, in the big leagues or maybe right on the horizon.”

So, here’s another question about Franco to think about heading into his first full season next year at age 21.

Can you imagine what he’ll do next?