Dockers' acting coach Eric Hall (center) and his team look on during a game against the Shanghai Titans in Chongqing this year. Provided to China Daily

"We have two training sessions every week, and one more tactics session during the season," Peng said.

He memorizes the football terms and tactics, going through them mentally in and out of the field.

"I love the concentration and passion needed for football. It provides happiness you can never get from other activities," he said.

"We use more than 10 tactics in a game. It requires teamwork and intelligence," Peng said.

But the 25-year-old, who works in the wine industry, said he had to work hard to buy uniforms and equipment.

"Entry-level equipment costs 2,000 yuan to 3,000 yuan ($320 to $480), and the better gear costs more," player Wu Peixuan said, adding that he bought his uniform and equipment overseas for nearly 9,000 yuan.

"Some players quit because of the expense," he said.

Players attributed the success of the team to their American coach, Chris McLaurin, a former football player at the University of Michigan.

"Foreigners are very serious during training. They don't see the game as just a game, but a kind of career that really matters," Peng said.

The coaching team, including McLaurin, lays out the plans and tactics for the Dockers.

"Once the plan is done, players have to follow it strictly. They don't need our impromptu 'tactics' on the field," Peng said, adding that the systematic methodology brought the team "close to professionalism".

Wu said the foreign coaches also brought cultural understanding to the team.

"Many people see football as a dangerous game. They are afraid of hurting people or being hurt. In fact, injuries can be avoided by appropriate training. Football is not a game about violence but intelligence," Wu said.

When McLaurin returned to the US, Eric Hall became the acting coach. The 24-year-old Iowa native has played football since he was 8.

"The first time I came to watch the team, it was exciting. The game is fun, and I can make friends here," Hall said.

Hall, who lectures in a university in the city, joined the team in August.

"The players are strong and athletic guys. They are quick learners," he said.

"But they are also beginners, and I need to tell them basic rules and fundamental stuff," he said.

The difference in the sport between the US and China is that many US schools have a team and Americans start playing football from childhood, he said.

But the Dockers are unfazed. They start the new season of the amateur league this summer, and they are aiming to win the championship again.

Sun Xiaochen contributed to this story.

Contact the writers at luowangshu@chinadaily.com.cn and tanyingzi@chinadaily.com.cn