KANSAS CITY — The Royals’ offense did what it could to catch up to the Rays on Tuesday night, but what transpired early ended up costing too much.

Another short start from Brad Keller and key defensive miscues for the second consecutive night gave the Royals a 14-7 loss to the Rays at Kauffman Stadium for Kansas City’s first series loss this season.

Keller allowed five runs and only made it through 1 2/3 innings, his second-shortest outing this season. The Royals’ Opening Day starter saw a turnaround in his mechanics in his start last week against the Angels, but the struggles that plagued him to start the season came back against the Rays. He walked three with one strikeout — and just three whiffs in the 54 pitches he threw.

But Keller wasn’t helped by his defense. In Monday’s loss, three of the four Rays runs were unearned because of errors. On Tuesday, Tampa Bay capitalized on more defensive mistakes from the Royals.

After the Rays hit back-to-back singles to start the game, Whit Merrifield rushed a double-play ball for an error, allowing a run to score. In the second inning, Keller issued a leadoff walk to Kevin Kiermaier before getting a ground ball to Merrifield behind second base. But instead of throwing to first base for the out, Merrifield tried to flip the ball to shortstop Nicky Lopez for the double-play ball. Lopez was too far away from the bag to make the tag in time, and no outs were recorded. No errors were issued, but Keller was out of the game later that inning after loading the bases with two outs. Reliever Jake Newberry walked in two runs before getting the final out.

Andrew Benintendi bobbled a single in left field in the sixth for the Royals’ fifth error in two days. Kansas City’s offense showed life throughout the game — including Carlos Santana’s fourth consecutive multi-hit game and Lopez’s two-hit game — but the Rays jumped on relievers Ervin Santana (two runs) and Kyle Zimmer (four runs) to build their lead.