There were times when the southpaw drove himself crazy looking at the statistics, trying to figure out what was different from last year. So he stopped trying to make sense of the numbers and focused on the process. His thinking was that if he did the little things right, the results would take care of themselves.
On Monday, Rasmussen allowed one unearned run on two hits and three walks while striking out seven batters over six innings in the Class A Advanced Jupiter Hammerheads' 2-1 win over the Fort Myers Miracle.
"I ran into a rough stretch where it seemed I couldn't get anything working," Rasmussen said of his first half. "If I pitched well, we wouldn't score any runs. When we scored runs, I didn't pitch well.
"We just hit the All-Star break, so it was time to get away from everything and clear my mind. I didn't get off to the start I was looking for so I wanted to get back to being myself and competing. It has to be you against the hitter rather than getting caught up with mechanics and the feel of your pitches. That was the biggest thing."
Miami's No. 9 prospect allowed a leadoff single to Daniel Santana to start the game. The second baseman then swiped second and came all the way around to score Fort Myers' only run when catcher Jacob Realmuto's throw got away from second baseman Noah Perio and skipped past center fielder Isaac Galloway.
Rasmussen then settled down and retired nine of the next 10 batters he faced. Despite allowing the first batter to reach base in three of the final four innings he pitched, nobody reached second against the 23-year-old.
"I thought it was pretty good," said Rasmussen, who has been working with pitching coach Joe Coleman on hitting his release point more consistently and taking some of the pressure off his arm.
"There were obviously some at-bats where I didn't execute, but I got back and tried to force contact when I was behind. Inning by inning, I was relying on different pitches. My curveball was working well and I was able to spot up my changeup when I got into fastball situations to get swing-throughs and popups."
Selected by the Marlins in the second round of the 2010 Draft, the UCLA alum has struggled at times in his second go-around in the Florida State League.
He went 12-10 with a 3.64 ERA in 28 appearances with the Hammerheads last season. He held opponents to a .254 average while striking out 118 batters over 148 1/3 innings.
This year, however, Rasmussen is 3-7 with a 4.26 ERA. He has surrendered three runs or more in 10 of his 14 appearances, and only once -- in a 4-0 shutout of the Miracle on April 17 -- has he put up zeros.
Rasmussen says the numbers aren't reflective of the process he's making in his third year as a pro. For that reason, he's decided to avoid the stats and focus on the things he can affect.
"The numbers are not as good as they were last year, but baseball can be a funny game. You can pitch well, but the results may not show it. That's how I feel a little bit," he added. "Last year in the first half, I was really up and down. I don't want to say I've pitched well this year, but I'm more consistent.
"Last year, I would give up eight runs in two innings then one run over my next three games. You can't get carried up in the results. I felt like I was driving myself crazy looking at the numbers. It's about doing the right things and going about it the right way day to day. I feel like I'm doing the things I need to do to get better. While it's frustrating, my time will come around."
Rasmussen hopes the short time off over the All-Star break will help him get back on track.
"I played some golf. I love playing golf," he explained. "It's a nice distraction for me. It's a nice way to mentally keep yourself sharp. It's just you and the ball. You don't need to worry about anything else as long as you execute. Then I just watched some baseball on TV and hung out and tried to get away from the problems I have been having."
On Monday, Jordan Conley pitched a perfect seventh inning in relief of Rasmussen and Grant Dayton worked around a walk in a hitless eighth. Closer Michael Brady completed the shutout by striking out the side in the ninth.
Fort Myers starter Cole Nelson (3-1) allowed two runs on four hits and four walks while striking out four batters over 6 2/3 innings in the losing effort.