CLEVELAND -- Six weeks from now, this can't happen again.

It probably won't -- at least not for the same reasons. When the Boston Red Sox return to Progressive Field to face the Cleveland Indians in a Division Series showdown that grows increasingly likely by the day, it will be October. And in October, Addison Reed will almost always be available to pitch the eighth inning.

Reed, however, was unavailable Monday night in a gut-punch of a 5-4 loss to the Indians. He threw 12 pitches one day earlier and 31 pitches two days before that. In all, he threw 57 pitches in five days last week. After checking with Reed, Red Sox manager John Farrell decided that the recently acquired setup man could use a breather.

But in the postseason, days off are built into the schedule every two or three days, which makes it easier for relievers to get their rest. That includes Craig Kimbrel, which might leave Farrell more inclined to go to his closer for a two-inning save if Reed isn't an eighth-inning option. But that option isn't on the table now. Kimbrel might be the best ninth-inning pitcher of this decade and is in the midst of perhaps his best season, but he was developed in the minors to work in one-inning increments and isn't adaptable enough to risk overextending in August.

Matt Barnes failed to help the Red Sox hold on to a one-run lead in the eighth, allowing a walk and a single to the only two Cleveland batters he faced. Rick Osentoski/USA TODAY Sports

"If I use Kimbrel tonight," Farrell said, "he's got the need for one, if not two days off."

Fair enough. But it's what the manager said next that amplifies the problem with the Red Sox's bullpen.

"That's why," Farrell added, "you need the contributions from everyone."

For as much as the Red Sox will lean on Reed and Kimbrel in the playoffs, they will need others to emerge as trustworthy options. The starting pitcher won't always go seven innings -- Eduardo Rodriguez lasted only 5 2/3 in the series opener against the Indians on Monday -- and the bridge to Kimbrel won't always be so clear.

When the Sox won the World Series in 2013, Farrell leaned on the late-inning trio of Craig Breslow, Junichi Tazawa and closer Koji Uehara. Who will emerge as the third option this year? Anyone?

Think of the next six weeks as an open tryout, as Farrell picks his spots to rest Reed and remains conservative with Kimbrel.

"We do have a sense of urgency every day to close games out, but with nearly 40 games to go, there are still health concerns and injury potential that has to be brought into this," Farrell said after seeing Indians relief ace Andrew Miller leave the game in the seventh inning with a recurrence of the knee injury that has sidelined him this month. "That's where the decision on who was available tonight came in."

On Monday night, the choice was Matt Barnes. Farrell said he was aware of Barnes' extreme splits (1.95 ERA at home, 5.53 on the road) but outlined three reasons for using him anyway to protect a 4-3 lead. First, he couldn't use Reed and wanted to avoid Brandon Workman, who threw 32 pitches this past Friday and 13 Sunday. Secondly, he liked righty Barnes against Francisco Lindor, who is weaker from the left side of the plate, and righty-hitting Austin Jackson. Lastly, Barnes has more experience in the eighth inning than Heath Hembree.

But Barnes walked Lindor and gave up a single to Jackson. On came Hembree, who struck out Jose Ramirez but gave up a game-tying single to Edwin Encarnacion.

If not Barnes, then who?

Joe Kelly has had his moments, notably a 22-inning scoreless streak that spanned more than two months. But his command still tends to be erratic, and he gets few swing-and-misses for a pitcher whose fastball averages 99 mph. Robby Scott profiles as more of a lefty specialist. Workman, a Farrell favorite, has ascended into a higher-leverage role, notwithstanding his allowing a ninth-inning leadoff double to Brandon Guyer, who scored from second base when first baseman Brock Holt threw away Roberto Perez's sacrifice bunt.

"That one’s on me," Barnes said. "I've got to be better in the eighth there, getting the leadoff guy to at least be competitive, to at least make pitches to force him to get his way on."

Barnes is right about needing to be better. In the playoffs, he shouldn't have to worry as much about the eighth-inning part.