ST. LOUIS -- This was not going to be a regular start for Roansy Contreras.

As the Cardinals began their festivities, recognizing Albert Pujols and Yadier Molina ahead of their final regular-season home game that the Pirates won, 7-5 on Sunday at Busch Stadium, Contreras walked to the bullpen alongside bullpen catcher Raul Hernandez.

As Adam Wainwright waxed poetic about his time with Molina and Pujols, Contreras began getting his arm loose, firing off throws to Hernandez.

As Molina fought back tears, Contreras, who had the outfield to himself, advanced out to 120 feet, firing frozen ropes into Hernandez’s awaiting mitt.

As Pujols offered gratitude, Contreras, who was only 16 months old when Pujols made his debut, entered the bullpen.

No, this was not going to be a regular start for Contreras, nor was it the start he would’ve liked to make in his final start of the regular season.

He allowed four runs (two earned) in three innings. He didn’t record a strikeout and walked two batters. His velocity, similar to his last outing, was noticeably down. Above all else, Contreras and Pujols will be forever linked after allowing a solo home run to La Máquina in his final regular season at-bat in St. Louis. It wasn’t the start that Contreras wanted to finish on, but a bitter ending does not take away from an encouraging rookie season.

“Overall, really positive,” manager Derek Shelton said. “There were so many things that Ro did well and things to build on for the next year.”

“Through the ups and downs, I was able to finish the season healthy,” Contreras said through team interpreter Stephen Morales. “Just learning from all the different games and different situations will help me for next year.”

Contreras ends his rookie season with a promising final line. In 21 games (18 starts), Contreras posted a 3.79 ERA and 4.38 FIP with 86 strikeouts across 95 innings. While Contreras pitched 34 1/3 innings across nine starts with Triple-A Indianapolis this season, he is a lock to be part of next season’s starting rotation.

When asked where Contreras has grown the most this season, Shelton pointed to Contreras’ ability to execute on days where the rookie didn’t have his best stuff.

“I think the ability to execute pitches when he doesn’t have his best stuff,” Shelton said. “There have been times where he didn’t have the curveball at all. There have been times where he didn’t have the fastball. The slider is a definite weapon, but the fact that he’s able to pitch without his best stuff at times, I think that’s a very good sign for us.”

The 22-year-old had his share of memorable outings. In his first start of the season, he pitched five scoreless innings with five strikeouts. On July 7, Contreras recorded his first quality start by throwing six innings of one-run ball with seven strikeouts against the Reds. In a stretch of four starts against the Braves, Phillies, Blue Jays and Cardinals, Contreras allowed just four runs across 23 1/3 innings (1.54 ERA).

“The future looks really bright here when it comes to pitching and the starting rotation,” Contreras said. “I feel like every day, things get better and better. It looks like it’s going to be a good future ahead of us.”