PHILADELPHIA -- The final week of the Phillies’ regular season carries importance, even after clinching the NL East title on Monday.

The Phillies (93-65) are still trying to clinch a first-round bye in the postseason, and they left Citizens Bank Park on Tuesday night one loss behind the 93-64 Dodgers for the No. 1 seed, following a 10-4 loss to the Cubs. But the Phils remain in a strong position to clinch the No. 2 seed. They only need a combination of two wins or two Brewers losses to do it.

But Philadelphia is also trying to set its 26-man postseason roster. It will include outfielder Austin Hays, who was reinstated from the 10-day injured list on Tuesday. It seems unlikely to include right-hander Taijuan Walker, who allowed three runs on four hits and three walks in 1 2/3 innings in relief.

Walker has a 7.10 ERA this season, which is the highest for any Phillies pitcher since 1931 (minimum 80 innings). It is the seventh-highest ERA in the Majors in the past 10 years.

• Postseason FAQ: What’s next for Phillies?

Walker got bumped from the rotation to the bullpen earlier this month, but after three rough starts from three alternates, he returned last week against the Mets at Citi Field.

It did not go well. So, Walker returned to the bullpen again. He replaced Tanner Banks with the bases loaded and one out in the second inning on Tuesday. Walker walked Miguel Amaya on eight pitches to score a run. He walked Ian Happ on eight pitches to score another run to make it 2-1.

The inning spiraled from there as the Cubs scored four more runs to give them a 6-1 lead.

“It’s kind of putting him in a tough spot, he’s never done that,” manager Rob Thomson said. “But we’ve got to find out [if he can do it].”

The Phillies might carry a 12-man pitching staff in the postseason, giving them eight relievers. Seven relievers are locks: right-handers Carlos Estévez, Jeff Hoffman, Orion Kerkering and José Ruiz; and left-handers Matt Strahm, José Alvarado and Banks.

It leaves one spot.

Thomson said the Phils have enough pitchers in the bullpen who can pitch two-plus innings that they don’t necessarily need somebody who is built up like a starter, who would only be needed in an extra-inning game or a blowout loss.

“We’re good with that,” Thomson said. “I think the way our guys are, Ruiz can go two, whoever that last guy [is] will be able to give us two or three.”

That last guy could be left-hander Kolby Allard, who struck out five but allowed four runs on five hits and one walk in four innings. But it also could be right-hander Spencer Turnbull, who has not pitched since late June. He is scheduled to pitch three innings in a live batting practice session on Friday.

The Phillies think Turnbull could help in the postseason.

There is no question they think Hays can help.

Hays had been feeling the effects of a kidney infection since early August, when he landed on the 10-day IL because of a strained left hamstring. Hays has played parts of seven seasons in the big leagues, so he knows how it feels when he is fatigued from playing.

This fatigue felt different. He was diagnosed with the infection in early September and he got on antibiotics.

It took more than two weeks to finally feel better.

“I really, truly physically just feel like Austin Hays again,” said Hays, who went 1-for-4. “My body feels great, mentally I feel really good, and what I can bring to this team and contribute.”

When the Phillies acquired Hays from Baltimore on July 26, they made him the everyday left fielder, despite drastic splits between lefties (.941 OPS) and righties (.548 OPS).

In the postseason, Hays could find himself in a platoon situation in left, but nobody has said either way. Brandon Marsh hits righties (.806 OPS) much better than lefties (.572 OPS), although he has hit lefties better recently.

Hays and Marsh could platoon in left, although Marsh can also play center.

Johan Rojas is Philadelphia’s best defender, so he could see the most time in center. Thomson raved about his two bunts in Monday’s NL East clincher, which are the types of small things they want him to do to keep his glove in the field.

The Phillies can also add the left-handed-hitting Cal Stevenson to the postseason roster. He was optioned on Tuesday to make room for Hays, but he will be eligible to return before the NL Division Series.

Weston Wilson, who hits right-handed, and Kody Clemens, who hits left-handed, are on the bench. Both can play left field as well.