Tanner Houck has established himself as the Red Sox closer, but he is ineligible to travel with the team to Toronto next week because he remains unvaccinated against COVID-19. Steven Senne/Associated Press

BOSTON — When the Red Sox visit Toronto next week, they’ll be without their new closer, Tanner Houck.

Houck, who has admirably assumed the ninth-inning role in recent weeks, remains unvaccinated against COVID-19 and is still ineligible to pitch in Canada, Manager Alex Cora said Monday. It’s unclear if any other players will be unable to make the trip; Kutter Crawford, who is currently at Triple-A Worcester, was the only other player who was placed on the restricted list when the Red Sox played in Toronto in late April. It’s unknown if any of the players who have been added to Boston’s roster since the last series are also unvaccinated.

“Tanner is not going,” Cora said.

From next Monday to Wednesday, Cora will have to get a bit creative when it comes to the ninth inning, much like he did for much of the early part of the season. Houck’s emergence as a trusted ninth-inning option has allowed Cora to finally structure his bullpen on a nightly basis with John Schreiber, Matt Strahm and others serving setup roles.

The fact Houck missed a start in Toronto in late April actually factored into his move to the bullpen. He was in the rotation for the first three turns through but has made his last 14 of his last 15 appearances out of the bullpen after Garrett Whitlock moved to the rotation. Houck has pitched in the eighth inning or later in his last seven outings and has recorded saves in his last five appearances. His save Monday night represented the first time in his career that he has pitched on back-to-back days.

Cora explained that Boston’s comfort level with some of its pitchers at Triple-A – including Josh Winckowski, Crawford and others – made the club decide to use Houck in relief while relying on others if rotation needs arose. Winckowski and Crawford have pitched admirably in fill-in roles since Whitlock and Nate Eovaldi went on the injured list earlier this month. Cora said the Red Sox never considered moving Houck back to a starting role when those two starters got hurt.

“We were trying to stretch him out but then we made the decision that, ‘OK, these kids are OK. They’re ready to go,’ ” Cora said, adding that there are others beyond Winckowski and Crawford that the club could turn to.

“We felt like we didn’t have to stretch him out the way we were doing in case something happened,” he added. “It’s where we’re at and where we’re going to stay and so far, if you take away the Angels’ outing (7 ER in 2 1/3 IP on May 5) that we had to actually stretch him out, he has been a really good reliever for us.”

Cora said he still views Houck as a starter on a long-term basis. Boston’s early-season bullpen issues necessitated Houck’s switch to a late-inning role in the short term.

“Every season is different,” Cora said. “Toward the end of the season last year, he was a reliever, just like (Whitlock). This team needed this as far as structure. For a month and a half, we struggled getting 27 outs.

“This is a decision we made a few weeks ago and for now, we’re going to stick to it,” Cora said.

RIGHTY JOSH WINCKOWSKI will remain in the team’s rotation – at least for one more outing.

Winckowski will pitch this weekend in Cleveland, Cora said Monday night. The rookie could pitch either Saturday on regular rest or Sunday if Garrett Whitlock is able to return from the injured list.

Boston’s pitching plans for the weekend are a bit up in the air. An off day Thursday gives Cora some flexibility. Nick Pivetta, who pitched Sunday, could go Friday on regular rest or Saturday if Whitlock comes back for the opener against the Guardians. The Red Sox could go with Pivetta, Winckowski and Rich Hill in Cleveland then activate Whitlock in Toronto, where a three-game series starts next Monday. Regardless of when he pitches, Winckowski – who was born in Toledo, Ohio – is excited to pitch in his home state.

“My grandparents still live in Toledo so they’ll definitely be there which will be nice,” Winckowski said.

Winckowski’s last two starts have earned him another chance in the majors. On Monday, he held the Tigers to two runs on seven hits in 6 2/3 innings while earning his second straight win. After struggling in his debut against the Orioles on May 28, he has pitched well against Oakland and Detroit in his last two outings. In total, he owns a 3.68 ERA in three starts.

Cora thinks Winckowski’s last two outings are more indicative of his potential than his debut, which came with the righty as the 27th man for a doubleheader against the Orioles.

“The first one is always tough,” Cora said. “Big-league debut knowing you’ll be back in Worcester in 24 hours. One outing, it’s hard to know who he is or what he’s all about but he has thrown the ball well lately. He’s pounding the strike zone, good stuff, secondary pitches are playing right now. Got some ground balls when we had to and that was enough today.”

Being with the Red Sox for the last week has allowed Winckowski to settle into a big league lifestyle.

“That definitely helped a lot,” Winckowski said. “The last outing, I kind of drove up here the day of, which wasn’t too bad but was a little out of the ordinary for a start day. Just being able to throw a bullpen here, lift here and do all that stuff here, it definitely helped a lot with comfort.”

“He has been here for a week,” Cora said. “Meetings, scouting report, following (Michael) Wacha and all the things that come with being a big leaguer. Now, at least he has five or six days which is very important for the progress of the player.”

Even when Whitlock returns, the Red Sox will still be without Nate Eovaldi, who is progressing slower than the team anticipated in his return from a back injury. Winckowski could theoretically remain in the rotation until Eovaldi returns or Chris Sale is activated form the injured list.

RED SOX STAR Rafael Devers is the leading All-Star vote-getter among American League third baseman so far, according to a voting update released by Major League Baseball on Tuesday. Devers has 727,669 fan votes, putting him ahead of Cleveland’s José Ramírez (711,367).

Xander Bogaerts (525,202 votes) ranks third among AL shortstops behind Toronto’s Bo Bichette (585,744) and Chicago’s Tim Anderson (528,278). J.D. Martinez (307,706) is third among designated hitters, trailing Houston’s Yordan Alvarez (835,669) and the Angels’ Shohei Ohtani (555,056).

Fan voting closes at 5 p.m. on June 30. At that point, the top two vote-getters at each position (and the top six outfielders) will advance to the next phase to determine who makes the All-Star teams and starts. All-Star starters will be revealed on July 8 and full rosters will be revealed July 10. The All-Star game will be held at Dodger Stadium on Tuesday, July 19.

Yankees star Aaron Judge is the current leading vote-getter (1,512,368) while former Red Sox star Mookie Betts (1,446,050) leads all National Leaguers.