Jake Arrieta needed to improvise.

The Phillies didn’t have access to Citizens Bank Park for four days last week while they waited to learn if COVID-19 infiltrated their clubhouse. But Arrieta hadn’t pitched in a game since a training-camp scrimmage on July 22. So he found a field in Haddonfield, N.J., not far from his house, rounded up a throwing partner, and got after it as best he could.

“Me and [reliever] Tommy Hunter stretched it out pretty good on two of those days,” Arrieta said Sunday. “Just getting the arm up overhead and getting it moving, even if it’s not off the mound, it’s better than nothing.”

Indeed, it will have to do. After idling for seven days, including the last three in which they didn’t receive any positive tests (or false positives, for that matter) for the coronavirus, the Phillies will finally resume their season Monday night in New York against the Yankees. And Arrieta, at long last, will make his first start of the season.

Well, maybe.

This being 2020, nothing is certain until it actually happens. These being the Phillies, no game is guaranteed to be played until they take the field. Keep an eye, then, on the forecast, especially with Hurricane Isaias set to bear down on the East Coast.

“Just another factor we are going to have to deal with, unfortunately,” Arrieta said. “It has been frustrating. But at the same time, I haven’t been dwelling on that too much because we are all in a really tough situation having to deal with so many different factors that have kind of derailed the beginning of our season. We knew these were going to be tough times, and we’re doing the best we can to stay ready.”

Some have had it tougher than others.

At one end of the spectrum, Yankees ace Gerrit Cole – scheduled to start Monday night – has thrown 177 pitches this season. At the other, all Phillies pitchers have combined to throw 428. Four Phillies pitchers – Arrieta, Zach Eflin, and reliever Jose Alvarez and Adam Morgan – haven’t appeared in a game yet.

The Yankees rode into their Sunday Night Baseball matchup with the Boston Red Sox with a best-in-baseball 6-1 record, including a five-game winning streak. The Phillies have played a total of three games and spent the last week giving saliva samples and going back home.

“Those days were tough not being able to come to the field,” Arrieta said. “To be shut down again like that was tough for all of us. It’s human nature to think, ‘Why us?’ Or [to say], ‘Poor Phillies, why did this happen?’ But once you have that initial thought and you get it out of your head, then it’s time to think about, ‘OK, what do we need to do to stay as ready as we possibly can even though it’s difficult?’”

Arrieta said he hasn’t heard from teammates who are thinking of opting out of the season, even as 20 members of the Marlins’ traveling party in Philadelphia tested positive for COVID-19 and another outbreak is occurring within the St. Louis Cardinals’ organization.

Milwaukee Brewers outfielder Lorenzo Cain on Saturday became the latest big name to opt out. The Phillies have players who might have reason to consider doing so. Shortstop Didi Gregorius, for example, has a chronic kidney condition.

“I think that some of those concerns might have been brought up during the original shutdown in spring training back in March, but now I think everyone here is eager to get back on the field and start to perform and get some wins,” Arrieta said. “In my mind, as good as we’re doing following all the protocols and trying to avoid getting sick and spreading it around our organization, it seems like no matter how many precautions you take, anybody could get COVID-19. You could get it from checking the mail or from going to the gas station.”

But Arrieta doesn’t believe, based on what he’s heard from the Players Association, that Major League Baseball will suspend the season unless “at least a handful of teams” are dealing with outbreaks.

The Phillies have other issues to worry about. It was always going to be challenging for pitchers to prepare for the rigors of a season during a training camp that lasted only three weeks. It certainly can’t help Phillies pitchers to have had a week off after only three games.

“I give our pitchers credit. They’ve kept up trying to do as much as they could by themselves,” manager Joe Girardi said. “I’ve heard [about] guys throwing baseballs against mattresses and brick walls on the outside of their homes and wherever they can.”

Arrieta said he has thrown a bullpen session every two or three days and even an 88-pitch simulated game since the season started. He believes he’s ready to face the Yankees and perhaps even go deep into the game if he sticks to his game plan of using his sinker to get contact early in counts.

“I believe baseball is a game with a lot of physical skill and ability, but it’s also a chess match, especially from the pitching side of things,” said Arrieta, who will be making his first start at Yankee Stadium since 2012. “I know I have the ability to pitch a lot of different ways. Whether my arm strength is ready for 100-plus pitches or not, I know there’s things that I can do to navigate a lineup and give my team what they need [Monday] night.”