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One a day the Texas Rangers designated a former Cy Young winner for assignment, starting pitching again was the issue.

Dane Dunning, one of the few bright spots on the mound over the last month, didn’t have it in Sunday’s 5-2 loss to the Boston Red Sox.

The Red Sox (67-68) won 5-3 on Saturday, 9-1 on Friday and rallied to take Friday's series opener 9-8.

Texas (58-75) has lost a season-high eight in the row and was swept in the four-game series at Fenway Park. The Rangers are a season-low 17 games under .500 with a three-game set at the American League West-leading Houston Astros starting Monday.

Dunning had gone 2-1 with three quality starts and a 3.52 ERA in seven outings since being activated off the injured list on July 26. Outside of staff ace Martín Pérez, few Rangers had been more reliable lately than Dunning.

That wasn’t so Sunday in Boston. The right-hander was tagged for five runs on eight hits in just four innings, taking to loss to drop to 3-8.

Staked to a 2-0 lead after the top of the first thanks to run-scoring double from Adolis Garcia and Jonah Heim’s RBI groundout, Dunning allowed four runs in the bottom of the inning.

Before the game, Texas DFA’d Dallas Keuchel. The 2015 Cy Young winner with Houston signed a minor league deal with Texas on July 26.

He lasted two starts, losing both with a 12.60 ERA, including Friday at Boston. The Rangers hoped Keuchel could provide some stability in the rotation after a promising showing at Triple-A Round Rock, but the lefty flamed out in similar fashion to earlier stops with the Chicago White Sox and Arizona Diamondbacks this season.

Pérez (10-5, 2.89) is scheduled to go against the Astros in Monday’s opener. Houston is countering with Hunter Brown, who is making his MLB debut.

You can find Art Garcia on Twitter @ArtGarcia92.

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