St. Louis’s Trevor Rosenthal, with catcher Yadier Molina, wasn’t called up to the big leagues for good until late August. (Jeff Roberson/AP)

— In spring training, Trevor Rosenthal was a 21-year-old starting pitcher who had never pitched at a level higher than Class A. He was, it seemed, closer to his days at Cowley County Community College than the majors. But at the St. Louis Cardinals’ facility in Jupiter, Fla., Rosenthal had access to major leaguers.

“He was a sponge,” Cardinals General Manager John Mozeliak said.

Rosenthal carted around a notebook. He talked with the veteran pitchers on the Cardinals’ staff, Chris Carpenter, Kyle Lohse and Adam Wainwright. He started the year at Class AA, bumped up to Class AAA, and in July was called up to the majors for the first time.

“It’s definitely been a quick ride,” Rosenthal said.

Headed into Sunday’s Game 6 of the National League Championship Series, Rosenthal had become a postseason force for the Cardinals — as a reliever. In six playoff appearances against the Washington Nationals and the San Francisco Giants, Rosenthal had thrown 62 / 3 innings and allowed no runs, one hit and one walk while striking out 11. And he has done it with a fastball that touches 100 mph in just about every outing.

“Watching this guy pitch is pretty phenomenal,” fellow reliever Joe Kelly said. “He’s hitting 100 every time he goes out there, and it’s pretty fun to watch.”

Rosenthal wasn’t called up for good until late August. On Sept. 14, he gave up two runs in two-thirds of an inning in a loss to Los Angeles, pushing his ERA to 4.11. But in seven subsequent appearances, as the Cardinals pushed to seize the NL’s final postseason berth, he didn’t allow a run in 71 / 3 innings. In fact, in that span, he allowed just four base runners — three hits and a walk. His ERA at the end of the season was 2.78, and he struck out 25 in 22 innings.

That just set things up for the postseason, in which Cardinals’ starters, headed into Game 6, only twice completed six innings. With the roles at the back end of the bullpen well-established — Edward Mujica in the seventh, Mitchell Boggs in the eighth and closer Jason Motte in the ninth — someone needed to get key outs in the sixth.

“We continue to give him high-leverage situations,” Cardinals Manager Mike Matheny said, “and he continues to execute his pitches.”

The cumulative result: Rosenthal hasn’t allowed a run in his last 14 innings. There is a chance, Mozeliak said, that Rosenthal could return to a role as a starter next spring. For now, he’s not worried about that. “Just show up and do what they tell you,” Rosenthal said.

Holliday is a Game 6 scratch

Matt Holliday, the Cardinals’ No. 3 hitter, was scratched from the lineup 45 minutes prior to Game 6 with lower back tightness. The Cardinals thus had to shuffle their lineup, moving cleanup hitter Allen Craig from first base to left field, inserting Matt Carpenter at first base and into the second spot in the order, and moving Carlos Beltran from second into Holliday’s spot.

Holliday has been in a funk during the NLCS — just 4 for 21 with no extra-base hits. Carpenter entered Game 6 2 for 6 in the series. He was the hero of Game 2, when he entered the lineup when Beltran came up with a balky knee and hit a two-run homer.

Red Sox turn to Farrell

The Boston Red Sox are hoping that two big trades will help them get back to the playoffs after missing out three years in a row.

The first was a genuine blockbuster that sent Adrian Gonzalez, Carl Crawford, Nick Punto and Josh Beckett to the Los Angeles Dodgers and freed up more than $250 million in future salaries. The second was the deal that brought John Farrell back to Fenway Park on Sunday.

The Red Sox hired Farrell to be their new manager after pursuing him for more than a year, agreeing to trade infielder Mike Aviles to the Blue Jays to pry their former pitching coach out of the manager’s chair in Toronto.

“I’m extremely excited to be returning to the Red Sox and to Boston,” Farrell said in a statement released by the Red Sox. “I love this organization.”

Farrell had been the Toronto manager the past two seasons, posting a 154-170 record with two fourth-place finishes. He had one year remaining on his contract with the Blue Jays, allowing them to demand compensation.

— Associated Press