And on the 21st day, they shall rest. Finally.

The Mariners completed a stretch of 20 games in 20 days to open the 60-game regular season on Wednesday with a 7-4 loss to the Rangers at Globe Life Field, despite a strong start from Taijuan Walker and home runs from Daniel Vogelbach and Austin Nola.

• Box score

Walker continued his comeback from a two-year Tommy John-surgery rehab by throwing six strong innings, marred only by an unearned run, to lower his ERA to 4.05 through four starts. But Seattle’s young bullpen gave up six runs, including five in the eighth, to spoil the effort.

Nola and Vogelbach provided the early offensive punch in a four-run second inning as Nola led off with a 424-foot blast to center field, and Vogelbach outdid him moments later with a two-run shot that traveled a projected 441 feet against Rangers starter Jordan Lyles.

The Mariners reached the one-third mark of the regular season at 7-13, and they now have a day off before continuing their eight-game road trip in Houston on Friday.

Here are three things we learned in the first 20 games:

The rotation is rounding into shape
While the Mariners have the highest team ERA in the American League (and 28th in MLB) at 5.66 and their young bullpen is going to have its struggles, they have been making strides with their six-man rotation, even after losing Kendall Graveman to a neck injury.

Rookies Justus Sheffield and Justin Dunn each earned their first career wins with strong showings in their last outings, and Nick Margevicius pitched well in a short start after shifting over from the bullpen to take Graveman’s spot.

No. 1 starter Marco Gonzales remains the steadying factor atop the rotation, while Yusei Kikuchi and Walker have been improving dramatically since their initial outings. Seattle's starters' ERA has gradually dropped to 4.75, which is 11th in the AL and 20th in MLB.

Walker was in control for six innings against the Rangers, and if you take away a fourth-inning blip in his last outing, he’s allowed only two runs (one earned) on eight hits over his past 16 frames.

“Taijuan was awesome,” manager Scott Servais said. “I can’t say enough about the job he did and his presence and how he took control of the game early on. And he just kept pouring it on.”

This team can run
For several years, the Mariners have talked about getting more athletic and attacking more on the basepaths. And with Mallex Smith and Dee Gordon in the lineup last year, they ranked third in the AL with 115 stolen bases in 162 games, with Smith and Gordon accounting for 68 of those.

But the current club has a lot more speed throughout the lineup and is tied for the AL lead with 19 stolen bases. Seven Mariners players have swiped a bag already, and Smith (two) and Gordon (none) have hardly been a factor.

Dylan Moore, who was caught stealing on nine of his 20 attempts last year, has been far more successful this year, as he shares the club lead with four stolen bases in five attempts after adding another Wednesday. Tim Lopes is 4-for-4 in limited playing time, while J.P. Crawford and Shed Long Jr. have three each.

Crawford totaled only five stolen bases last season, so he’s taken a much more aggressive approach already in his new leadoff role, and Kyle Lewis is capable of running as well, though he’s only stolen one base so far.

The young bucks will ride the waves
On one hand, you’ve got Lewis tearing things up, as the rookie center fielder added his 14th RBI with a sacrifice fly on Wednesday and is still batting .338 with four homers after an 0-for-4 showing. A third of the way through the season, he’s a legitimate AL Rookie of the Year Award candidate.

Crawford has also been impressive, with the shortstop having reached base in all 19 of his games after going 2-for-4 with a walk to raise his on-base percentage to .405. Crawford has been outstanding defensively and -- after making a throwing error to allow Walker’s unearned run in the sixth -- immediately responded with an outstanding diving stop and glove flip to Long at second to get out of that frame.

On the other side, there’s first baseman Evan White -- trying to make the same jump straight from Double-A that Lewis began last September -- hitting just .104 with 31 strikeouts in 73 plate appearances.

“He’s learning a lot right now,” Servais said of White. “Sometimes, life’s toughest lessons are hard to go through. Everything he’s looking for is all within himself. I saw Evan turn around a 98 mph fastball in Summer Camp and hit it out of the ballpark. I’ve seen him take two-strike sliders and slap them into right field and drive in runs. It’s all in there. Now, it’s what do we need to do to let it all come out?”

The bullpen is also filled with youngsters and, as with Erik Swanson in Wednesday’s late meltdown, they’re learning on the fly. The 26-year-old was throwing 98-99 mph heat as he struck out Nick Solak to start the eighth, but he lost his command and the lead, allowing five runs on three hits and a pair of hit batters.

“Giving young guys opportunities in those spots is really, really valuable,” Servais said. “They will learn from it, and we will benefit from it down the road. It’s just a little painful tonight when we didn’t get the ‘W’ after we were in control of that ballgame.”