Nathan Eovaldi, left, and Chris Sale, are the Red Sox best starting pitchers and will need to come up big for Boston to hold onto its wild-card position. Associated Press photos

The health of a pitching staff can make or break a team’s playoff hopes.

The Toronto Blue Jays were reminded of that Sunday morning when they placed starter Hyun-Jin Ryu on the 10-day injured list with neck tightness. Hours later, fans at Fenway Park held their collective breath when Red Sox pitcher Garrett Whitlock motioned to the dugout and left the mound during the seventh inning with tightness in his right pectoral.

Losing Whitlock, or anyone at this point, would be a blow to the postseason hopes of the Red Sox. Depth is critical to a team’s success. But as we close in on October baseball, the bottom end of the roster is far less important than the top. In fact, you could argue that stretch run of the 2021 Red Sox season rest on the arms of two pitchers.

Chris Sale and Nathan Eovaldi are Boston’s best pitchers. Together they represent Boston’s best hope for any sort of October run.

Eovaldi has been the team’s best starter all season. He leads the team with 30 starts and has thrown more innings than any other pitcher on the team. In fact, this is the most innings he has thrown in a season since 2014 when he came within an out of reaching 200 innings.

Eovaldi has been the Red Sox MVP this season. With the absence of Sale for the first four months of the season after Tommy John surgery, and the uncertainty of Eduardo Rodriguez after he missed all of last season with COVID-related myocarditis, Eovaldi has delivered every fifth day, serving as the rock this rotation has been built on.

Over the past eight starts, Eovaldi has posted a 2.27 ERA, striking out 64 batters while walking only eight. He has struck out at least eight batters in each of his last four starts — the longest such streak of his career. It’s the kind of numbers you expect from the ace of a team closing in on a playoff spot.

“We’re coming off of five (consecutive) wins now,” said Eovaldi after Sunday’s game. “With that momentum coming into the schedule that we have, it’s going to be key for us to, you know, continue that success and try not to look too far ahead and focus on our goal.”

To achieve their goal the Red Sox will have to pitch well over the next two weeks and beyond. Enter Sale. He made his first start of the season for Boston on Aug. 14. Then came a stint on the COVID-related IL last week. He returned on Friday, beating the Orioles to open up the homestand. The Sox have won five of Sale’s six starts.

Manager Alex Cora has made it clear he is pinning his team’s hopes on the two pillars of his pitching staff. He will use them as much as possible down the stretch, likely having one of the two start half of the team’s final 14 games. Rodriguez and Nick Pivetta would round out those starts, with Tanner Houck moving to the bullpen (where he has yet to give up a run in three relief appearances.)

It’s also the blueprint for the team’s postseason hopes. Get Eovaldi and Sale to start as many games as possible, and hope to patch together the rest.

Cora is hoping the plan summons the memories of 2013. Jon Lester and John Lackey started nine of the team’s 16 postseason games, and were the winning pitchers in seven of the team’s 11 playoff victories that year.

“We’ve been getting a lot of extra days with days off and extra arms and things like that,” said Sale after his start Friday night, “but this is what I’m used to. Hey, these are big games coming up. They’re all big games. Down the stretch we’ve got to make a good final push to break the seal and get to the postseason. It’s all hands on deck and whatever they need they need — and I’ll give it to them.”

That’s what the Red Sox are banking on. That Sale and Eovaldi will give it to them every fifth day. If they can do it over these final two weeks of the regular season, they will get to keep doing it in the postseason.

Tom Caron is a studio host for Red Sox broadcasts on NESN and a Lewiston High School Graduate.