Ann Andrews woke up Tuesday morning with a knot in her stomach.

The longtime Severna Park field hockey assistant and veteran club coach was set to make her debut leading the Falcons, whose program-founder and 20-time state champion Coach Lil Shelton retired after her 37th season last fall.

“I woke up with the worst stomachache and I know it’s from stress,” Andrews said with a laugh. “I certainly want us to maintain our high level of success, and if we don’t, it does fall on me.”

Severna Park’s opener didn’t go as planned Tuesday night – senior attacker Abbey Meehan scored twice to lead No. 4 Broadneck to a 2-1 win – but behind returning All-Met Marissa Balleza and senior attackers Sam Slattery and Adley Beairsto, No. 5 Severna Park remains a favorite to win the Maryland 4A championship even with a new coach at the helm.

“They have a lot of their big players back,” South River Coach Katie Corcoran said. “They’ll be just as strong as ever.”

Corcoran’s Seahawks open the season No. 1 in The Post’s Top 10, after they beat Broadneck, 2-1, in the teams’ openers last Friday.

The three traditional Anne Arundel powers will again battle for the county title, which South River won last year, and the Maryland 4A East crown, which Severna Park has won every year since moving up to 4A classification in 2007.

La Salle recruit Abbey Lawrence and fellow seniors Jennie Milligan and Taylor Bresnahan will pace South River, while Broadneck has 15 seniors and 17 total returnees on its veteran squad.

“The top tier in our county will be very strong again,” Corcoran said.

South River will face another major test Saturday morning, when they host No. 2 Glenelg in the semifinals of the South River Invitational Tournament at 9:45 a.m.

The Gladiators lost All-Met Player of the Year Alyssa Parker (Maryland) and first-team All-Met Mary Kate Olson (Franklin & Marshall) to graduation from their back-to-back Maryland 2A championship squads, but return a strong group that includes junior midfielder Morgan Philie, a Junior Olympian.

Westfield learns from early losses

Defending Northern Region runner-up Westfield already has two losses this season, both to reigning state champions — Virginia AAA school First Colonial and four-time defending Virginia AA champ Tabb.

Those humbling 5-0 and 6-2 setbacks, respectively, served their purpose.

“I knew they would be very, very tough games and they don’t mean anything to us except they’re a learning tool for the girls,” Westfield Coach Starr Karl said. “In the end, it just means they need to work a lot harder and that we have a lot of room to grow.”

Karl’s daughter, Shannon, is now the head coach at Virginia Commonwealth after serving there as an assistant for five years.

No. 6 Westfield and No. 7 South County, which met in the region final last year, are the consensus favorites again this season. Westfield beat the Stallions, 3-0, on Aug. 25. The teams will play again Sept. 27, at South County.

Westfield returns All-Met senior midfielder Meghan Winesett (Delaware), the 2011 region player of the year; second-team All-Met junior defender Rachael Ulsh and honorable mention All-Met senior goalie Lauren Saltus (Hofstra).

South County, aiming for its third region title in four years, has only four seniors, including forwards Alexis Schramm (VCU) and Stephanie Halsted.

Fairfax lost 11 players, including nine starters, but what the three-time defending Liberty District champion Rebels might lack in field hockey experience they can often compensate for with athleticism.

“We’ve been lucky that we’ve had some of the best Fairfax High School athletes on my team,” Rebels Coach Amber Beaudoin said. “Athleticism is its own reward. You just need to attract those kids.”

Fairfax senior midfielder Sam Zelenack has committed to Towson.

The Post Top 10

Defending Anne Arundel champion South River will face defending Howard and Maryland 2A champion Glenelg on Saturday morning...St. Stephen's/St. Agnes has won the ISL title in nine of the past 10 years...Westfield and South County are the favorites to emerge from the Virginia AAA Northern Region.

(Last year’s final record in parentheses)

1. South River (16-2)

2. Glenelg (18-1)

3. St. Stephen’s/St. Agnes (17-5)

4. Broadneck (11-5)

5. Severna Park (17-2)

6. Westfield (20-4)

7. South County (19-6)

8. Lake Braddock (17-4)

9. Holy Cross (16-5)

10. Wootton (8-5)