– Given the size of the video boards at CenturyLink Center, David Plummer found it nearly impossible not to sneak a glance. Cruising down lane 4 in the men’s 100-meter backstroke, with a world record in his sights Monday night, he didn’t want to look — or think — about his time.

All Plummer really wanted was a good swim in the semifinals at the Olympic trials and a spot in the finals Tuesday night. He got it — and in the process, the former Gopher edged closer to the world and American records while lowering his personal-best mark. Most importantly, Plummer, of Minneapolis, moved within sight of the Olympic berth he has chased for more than four years.

Plummer clocked a time of 52.12 seconds to top a stellar field in perhaps the deepest event at the trials. Just after Ryan Murphy threw down a time of 52.28 — momentarily displacing Plummer as the fastest in the world this year — Plummer one-upped him, adding to the hype surrounding Tuesday’s finals.

Minnesota-connected swimmers experienced an emotional gamut on Day 2 of the trials. The women’s 100 backstroke prompted exhilaration for 14-year-old Regan Smith of Lakeville, who finished 13th, and heartbreak for 2012 Olympian Rachel Bootsma of Eden Prairie, who fell short of advancing to the semifinals by .02 of a second.

As pleased as Plummer was, he’s hoping to be even happier Tuesday.

“I knew it was going to be fast [Monday],” he said. “It’s something I had to be ready for. [Murphy’s performance] was a great swim.

“He’s got more in him, so it should be a fun final. I hope we can find a little more in the tank [Tuesday] night.”

The roster for the Rio Olympics expanded on Day 2 of the trials, with winning swims by Katie Ledecky (women’s 400 freestyle), Kevin Cordes (men’s 100 breaststroke) and Kelsi Worrell (women’s 100 butterfly). Dana Vollmer, who finished second in the 100 fly, made her third Olympic team, while Ledecky fell just .61 of a second short of her own world record with a time of 3:58.98.

Plummer clocked the swiftest time in the morning preliminaries, finishing in 53.22 seconds. The controlled yet speedy swim was just what he was looking for, and he predicted the semifinals would be significantly faster.

In the first heat, Murphy — a three-time NCAA champ in the 100-yard backstroke at Cal — topped the 52.40 Plummer swam earlier this month, the world’s fastest time this year. He did peek at the video board, seeing he was close to the world record of 51.94.

“I didn’t necessarily expect to go that fast,” Murphy said. “I saw I had the world record going on, and I was going to stroke down, but I think that made me go a little faster than I wanted to the last 15 [meters].”

Plummer resisted the temptation to look, and it served him well. After finishing third in the 100 back at the 2012 Olympic trials — missing the team for London by .12 of a second — he is in strong position to make his first Olympic team at age 30. The final is expected to be a tight battle between Plummer, Murphy and 2012 Olympic gold medalist Matt Grevers, who qualified third in 52.64.

“Oh yeah, for sure,” Plummer said when asked if he was nervous about the final. “But it’s exciting. It’s a good place to be.”

Bootsma finished 18th in the preliminaries of the women’s 100 back. The top 16 swimmers advanced to the semifinals, and her time of 1:01.34 was .02 behind 16th-place Taylor Garcia.

A relay gold medalist at the 2012 London Olympics, Bootsma was seeded eighth in the 100 back, her signature event. She was in good position early, with a swift opening split of 29.44. But she faded quickly over the final 50 meters to fall out of contention.

Smith said she was more anxious for the preliminaries than she was for the semifinal, when she raced in a heat with Olympic superstars Natalie Coughlin and Missy Franklin. She will swim the women’s 200 back on Friday.

“I thought it was great,” she said of Monday’s semifinal. “It’s been a great experience and a lot of fun. I’m excited to see what I can do next.”

Olivia Anderson of Edina and former Gopher Haley Spencer also swam in Monday’s semifinals of the women’s 100 breaststroke. Spencer — who was 17th in the prelims but made the semis after another swimmer scratched — finished 12th, and Anderson was 14th.