ST. LOUIS -- In a packed car with his baseball equipment and belongings for the summer, Jacob Buchberger was on the road Sunday, about 15 minutes away from Chicago, when his phone rang.

It was the Cardinals, offering a free-agent contract. For Buchberger, a corner infielder and pitcher at Davenport (Mich.) University, the answer was an easy yes. He and his parents -- who were in a car behind Buchberger helping him move to North Dakota for summer ball -- rerouted to make an impromptu family road trip after Buchberger’s summer plans changed. One of the stops was Dyersville, Iowa, the Field of Dreams site. That’s where Buchberger officially signed Monday.

“It was one of those things here you’re waiting for it, you’re not sure it’s going to come, and then it finally comes, and it’s just a relief,” Buchberger said. “And it’s a dream come true.”

• Team-by-team: Undrafted free agent signing tracker

Waiting and anticipation fill the minds of many undrafted free agents in a market that started Sunday for players who were not selected in the shortened five-round MLB Draft. Teams could sign an unlimited number of undrafted free agents. They could not contact players until 8 a.m. CT Sunday and could offer a maximum of $20,000 to sign. It’s a market unlike anything amateur baseball has ever seen.

As the Cardinals continue to work to sign their seven Draft picks, they also have added eight new prospects through free agency, making them among the most active teams during this period.

This year’s undrafted free agents possess some leverage in choosing their destinations. With money no longer a separator, teams have to convince players to sign with them. Six of the eight players the Cardinals added were college seniors, but they all had one more season of eligibility after the NCAA granted an extra year to all spring sports athletes.

“The biggest thing for me was my age,” Buchberger said. “I’m 22 right now, so if I went back for another year, I’d be 23. Not many people can make it up to the big leagues when they get drafted at 23. It’s just that much harder. It’s more analytics-based, and that played a huge factor, even with how I was going to get signed money-wise. So that made a difference.”

Buchberger hit .415/.491/.702 in his career, including 32-for-61 (.525) in 15 games in 2020, with the Panthers. He struck out just 40 times across 376 career at-bats. The Cardinals plan on developing him at third base.

Left-handed pitcher Mac Lardner was one of the first agreements Sunday. With interest from around the league, the recent Gonzaga graduate was originally projected to go in the middle or later rounds before the Draft was shortened. Lardner is at home in Templeton, Calif., and started receiving calls at 6:05 a.m. PT, five minutes after the signing period opened. He said 10 teams called him Sunday, and in choosing which team to start his professional career with, he focused on the relationships he had built and what the player development system looked like.

The Cardinals had been scouting Lardner since his junior year, and he has a good relationship with the area scout, Chris Rodriguez. St. Louis’ player development system is highly touted across the industry, and Cardinals officials spent time discussing with Lardner how they saw him fit into the organization.

Like Buchberger’s, Lardner’s answer to the Cardinals’ offer was an easy yes.

“Really the biggest question I asked myself was, ‘What’s going to make me the best pitcher I can be?’” Lardner said. “And I believe the Cardinals are the answer. They have such a great organization with the personnel and the guys they bring in for coaches. They wanted to show that off. They used that to their advantage, and they really marketed themselves that way.”

Armed with three plus pitches, Lardner has a smooth delivery and is projected to add strength onto his 6-foot-4 frame. He became a full-time starter his sophomore year and posted a 3.75 ERA in 249 2/3 innings across four years with Gonzaga. In the Cape Cod League last summer, he was named an All-Star with a 2.25 ERA and 31 strikeouts next to three walks in six starts.

Lardner’s teammate at Gonzaga, right-hander Nick Trogrlic-Iverson, was almost certain he’d be going back to school for another year. After the Brewers selected him in the 15th round of the 2018 Draft, Trogrlic-Iverson transferred from Central Arizona Community College to Gonzaga.

A vastly different market awaited him this year.

Trogrlic-Iverson was ranked 25th on Baseball America’s top undrafted seniors list after posting a 4.75 ERA across 30 appearances (11 starts), but he didn’t know what would happen Sunday. Questions filled his mind as he tried to keep busy. The Cardinals were the first team to call him in the afternoon. They sold Trogrlic-Iverson on their player development system.

“It was a lot of uncertainty,” Troglic-Iverson said. “Is this something that’s going to happen for me? Is it right for me? Are they looking at me? A lot of sitting there, anticipating, but there’s nothing you could do but wait. It’s been a really weird time.

“Ultimately, I thought it was a good time for me to enter professional baseball, and this was a good chance for me to show what I have in an organization that prides itself on pitching.”