HOUSTON — Eduardo Nunez’s return to the Boston Red Sox lineup was even shorter than than last time.

Nunez reaggravated his right knee injury on his first-pitch groundout in the first inning of Game 1 on Thursday, limping down the line before collapsing short of the bag. He was carried off the field by Manager John Farrell and the trainer, Masai Takahashi.

While the Red Sox announced his status as “to be determined” for the series, he seems all but certain to be replaced on the ALDS roster, most likely by Chris Young. That would render Nunez ineligible for the ALCS, but his health seems to make that point moot.

Nunez initially suffered a strain of the posterior cruciate ligament in his right knee on Sept. 9. He came back for one game on Sept. 25, leaving after two at-bats because of renewed pain in that knee.

Over the last week and a half, the Red Sox worked to get Nunez in shape for the postseason. He participated in a simulated game Monday, getting six at-bats against Roenis Elias and breaking out of the box to run the bases. The Red Sox believed he looked good enough to merit not only a spot on the postseason roster but a start over Hanley Ramirez in Game 1 against Justin Verlander.

Instead, Nunez was replaced by Ramirez the second time through the order in the third inning. With Nunez likely unavailable, Young may move from off the roster to into the starting lineup for Game 2.

DOUG FISTER will start Game 3 of the American League division series for the Red Sox, but the Game 4 starter will depend on how the first three games unfold.

Rick Porcello and Eduardo Rodriguez will be available out of the bullpen in the first two games of the series.

“Wait and see how things unfold,” Farrell said, regarding Game 4. “(Porcello) will be in the bullpen the first two nights for sure providing length if needed and available for Game 4 depending on what transpires.”

At this point it seems Farrell wants Rodriguez more in a bullpen role while leaning to Porcello starting Game 4, if he isn’t needed in the first few games.

“We’ve got some internal discussions that have already taken place to line people up so they can take care of their work,” Farrell said. “But Game 4 has a definite thought attached to it. We’ll see how it unfolds.”

As for Rodriguez, he’ll be Boston’s only left-hander in the bullpen aside from David Price.