JUPITER, Fla. -- One week remains in Spring Training, and the Marlins still have some unfinished business when it comes to the rotation.

Aside from Jose Urena, already announced as the Opening Day starter, the rest of the rotation remains in flux.

The Marlins are open to carrying six or even seven candidates for five spots, with the other one or two available in relief or to spot start.

Manager Don Mattingly said on Monday that the organization is keeping its options open.

“We’ll leave ourselves some options and variations of it,” said Mattingly. “We don’t know who the five or six are going to be. We’re probably getting closer to the first few slots and how we’re going to line it up.”

Urena, Dan Straily, Pablo Lopez, Sandy Alcantara, Trevor Richards, Caleb Smith and Wei-Yin Chen are the candidates.

Based on how the rotation is lined up right now, there is a little bit of clarity.

Urena pitched in a Triple-A game on Monday morning on a back field on the Cardinals' side of the Roger Dean Chevrolet Stadium complex. The right-hander gave up one earned run on four hits in six innings, striking out two with no walks. Urena threw 70 pitches, 45 for strikes, with a fastball in the 93-95 mph range, topping out at 96 mph.

Straily is scheduled to face the Mets on Tuesday in Jupiter, and Lopez is scheduled to go Wednesday when Miami visits the Cardinals.

“As this thing keeps churning, our guys don’t necessarily know,” Mattingly said. “We’re not going in telling guys, ‘Hey, you’re going to start here.’

“We’re slowly working towards where we may flip a day or push a day until you line them up right, because you want extra rest.”

The Marlins open the season at home against the Rockies on March 28.

Regardless of how the rotation is set, at least for the early part of the season, it is expected to be subject to change.

The Marlins have used 12 starters in each of their past six seasons, and depth inevitably will be needed. Smith, who started against the Nationals on Monday, is building up in his recovery from left lat surgery. And Lopez, 23, missed last September due to a right shoulder issue. Both are healthy, and they have arguably been two of the best starters this spring.

Some of the younger pitchers will have their innings monitored, which also factors into how the rotation is set.

So if Chen were to start in the bullpen, the 33-year-old left-hander still would be a candidate to join the rotation at any point.

Chen has struggled this spring with a 9.53 ERA with five strikeouts in 11 1/3 innings. But the veteran has a track record, with 170 big league starts, including 26 in 2018 while posting a 4.79 ERA.

Alcantara, 23, has had some ups and downs this spring, with a 4.70 ERA, 21 strikeouts and 11 walks in 15 1/3 innings.

Straily, the expected No. 2 starter, has a 7.15 ERA in 11 1/3 innings. But he’s a proven big leaguer who made 23 starts a year ago.

“It’s always that Opening Day is a big thing,” Mattingly said. “And we love to use numbers -- two, three, four -- because you’re going to rate who we think is the best or whatever.”

Mattingly notes that after the first time through the rotation, with days off and other factors, starters' usage could be fluid.

Richards, for instance, has been lined up as the fifth starter. But the way he’s thrown in Spring Training, he’s making a case to move up to No. 2.

Richards threw six no-hit innings against the Cardinals on Sunday, and in 19 1/3 innings in Spring Training, the 25-year-old is 2-1 with a 1.86 ERA and 20 strikeouts.

“It’s been happening all spring,” Mattingly said. “We’ve seen adding the pitches and what it can do for him. So it’s been building. For Trevor, we’ve seen the consistency of it. You’re seeing it, not once, not twice. Now, it’s three times. This is trending in the right direction.”