Seventy-one regular-season games later, the Rangers are a reminder that roster construction is as much an art as a science.
Desmond hasn't just contributed -- he has been the club's best offensive player (.312, 11 homers, 46 RBIs). Mazara, Profar and Bush have been significant pieces after beginning the season in the Minor Leagues.
And the Rangers appear to be the American League's best team by a wide margin at this point. At 46-25, they lead the AL West by 9 1/2 games. They're 24-6 since May 20 and 15-4 in June.
Perhaps some of their numbers are unsustainable. For instance, they're 17-4 in one-run games. They've played four straight one-run games, and they've won them all. They've come from behind to win 23 times, the most in the Majors.
Over the weekend, the Rangers twice rallied to beat the Cardinals after the seventh inning. On Monday, they overcame an early 3-0 Orioles lead to win, 4-3.
The Rangers are an example of how the best teams, many times, are the deepest teams.
This is part of the genius of Rangers general manager Jon Daniels, whose club appears headed to the postseason for the fifth time in seven seasons.
Since he added left-hander Cole Hamels, reliever Jake Diekman and Dyson at the Trade Deadline last season, the Rangers are 85-47. Only the Cubs (90-39) have been better in this stretch.
So winning is nothing new for the Rangers. How they've done it this time is.
1. Desmond delivers
Desmond, who was still a free agent in late February, was signed to a one-year, $8-million deal when the Rangers became concerned -- rightly, as it turned out -- that Josh Hamilton would not be able to play.
Daniels saw Desmond as someone who would add talent to the organization and give manager Jeff Banister a nice option in left field. Desmond would also buy some more time for Mazara, the organization's top prospect, to continue his development.
Desmond, a former All-Star shortstop, has responded by having one of his best offensive seasons and contributing in both left field and center.
2. Mazara shows maturity
Mazara was 20 on Opening Day and had played just 20 games above Triple-A. The Rangers believed he had a chance to be an impact player, but also thought more time at Triple-A would benefit him.
That timetable changed when Shin Soo-Choo got hurt. Mazara made his debut in the seventh game of the season, and he has looked comfortable from Day 1. He leads AL rookies in hits (71) and RBIs (30) and is second in home runs (11) and third in batting average (.292). When Choo returned, the Rangers had to find a permanent place for Mazara.
3. Profar picks it up
Profar's career was derailed by injuries for almost three seasons, and the Rangers would have been thrilled if he'd had a healthy and productive comeback season at Triple-A. But he was playing so well that his promotion was automatic when second baseman Rougned Odor began serving a seven-game suspension for punching Blue Jays slugger Jose Bautista.
Profar hit .364 in those seven games, and he has not slowed down. Banister has started him at second, third, first and designated hitter and will continue to figure out how to get him and his .349 batting average in the lineup.
4. Bush a bullpen buttress
Bush was signed to a Minor League contract last December. The Rangers simply thought the No. 1 pick of the 2004 Draft (by the Padres) had the talent made him worth a look, despite past legal trouble. If he could straighten out his life, he could contribute. Bush was 30 when he made his Major League debut on May 13. In 18 games, he has been as good as almost any reliever in baseball, consistently throwing 95 mph and compiling a 1.08 ERA. So when Tolleson struggled, Banister moved Dyson into the closer's role; he's 10-for-10 in save chances. Bush moved into the eighth-inning role and allowed three baserunners and no runs in eight appearances this month.
5. Rotation rules
Both Perez and Lewis have bounced back in 2016 after struggling the final two months of the '15 season. Lewis has been one of the AL's best starters (6-0, 2.81). Perez (6-4, 3.57) has been solid enough that Darvish's return trip to the DL hasn't caused even a speed bump for the club.
As with most first-place teams, the Rangers are getting contributions from up and down the roster. Their best players, Hamels and third baseman Adrian Beltre, have been solid as usual.
First baseman Mitch Moreland has overcome a slow start to homer five times in his last 10 games. Shortstop Elvis Andrus has been his usual solid self.
In short, it's all working. Maybe not the way it was expected to work, but the view from first place looks the same.
Richard Justice is a columnist for MLB.com. Read his blog, Justice4U. This story was not subject to the approval of Major League Baseball or its clubs.