ARLINGTON — First things first: The Rangers rotation — largely the same unit that kept the club afloat last season amid a significant offensive drought — has an issue. 

It won’t take an observer long into any game to identify. 

The Rangers have been baseball’s worst statistical staff in the first inning of games this season, and in a 5-1 loss vs. the Houston Astros at Globe Life Field Thursday night, the early-contest struggles manifested themselves again. Rangers right-handed pitcher Nathan Eovaldi allowed five earned runs, three on a pair of first-inning home runs, and created a deficit that the team’s pedestrian offense can’t easily climb itself out of. 

The rotation owns a league-high 7.23 ERA in the first inning of games this season, and while their 3.34 ERA in frames two-through-nine is the fifth-best league wide, the early holes are an unsustainable problem given the club’s personnel. They allowed at least one run in two of their three losses to the Astros this series and, in the process, lost six games in a seven-game stretch and fell to fourth place in the American League West standings. 

They’ve allowed a league-high 19 first-inning home runs through 56 games and are on pace to allow 54 first-inning home runs this season. Only three teams — the Baltimore Orioles (43), the San Francisco Giants (43) and the New York Mets (40), each in 2019, the peak of the league’s juiced ball era — have allowed 40 first-inning home runs or more in a single season. Eovaldi’s eight home runs allowed in the first inning are the most in baseball while right-handed pitcher Jacob deGrom’s six are tied for the second-most.

“I don’t know if it’s just coming out and trying to be too aggressive and trying to make perfect pitches right away,” Eovaldi said, “as opposed to having a good mix and executing a little better.”

The former allowed two in the first inning of Thursday’s loss, the first to shortstop Jeremy Peña on a splitter and the second to third baseman Isaac Paredes on a sinker. The 36-year-old thought his pitch to Peña, the fourth he threw all game, was a “bad splitter.” Eovaldi was ahead of designated hitter Yordan Alvarez before he walked him and threw what he thought was a well-executed sinker that was sent over the left field wall. He pitched six more innings after that, and in the second, allowed two more runs on a double, single, walk and wild pitch.

“The first inning is the tale of the game,” Eovaldi said. “It was over at that point.”

It is if the club’s offense can’t bail out its starter once in a while, something which developed into an issue last season when the rotation was baseball’s best, and something that’s become an equally worrisome trend this year as the staff’s taken a step back. The Rangers totaled four hits against Astros right-handed pitcher Spencer Arrighetti and three relievers. They scored one in the second inning on third baseman Josh Jung’s solo home run and finished hitless in six opportunities with runners in scoring position. Outside of Tuesday’s win, in which the Rangers scored eight runs in the first inning, they scored four runs in their three losses vs. the Astros this week. 

“It’s tough,” Urueta said. “Everybody knows, it’s not a secret, that if you put up a three-spot in the first inning, now the offense has to work a little bit harder.”

That’s a precarious place for this team to be in.