Two South Korean football clubs that faced each other last week have been struggling to contain the spread of the novel coronavirus inside their locker rooms, with another matchweek on the horizon.

Ulsan Hyundai FC extended their lead atop the K League 1 tables by beating FC Seoul 2-1 last Friday. In the ensuing days, both clubs have seen multiple COVID-19 cases pop up.

Ulsan had to play a playoff match at the Asian Football Confederation (AFC) Champions League on Tuesday severely undermanned -- to a degree that their 37-year-old player-coach Lee Ho, who didn't appear in any match last year, had to dress and sit on the bench as a possible substitute.

Though Ulsan haven't disclosed the exact number of ailing players, they have at least 10 players on the shelves after adding seven to the list Wednesday.

FC Seoul, which first reported a handful of cases on Tuesday, had 11 players who tested positive for the virus as of Wednesday.

Through five matches, Ulsan are the only undefeated team in the league with four wins and a draw. FC Seoul have one win, two draws and two losses.

FC Seoul will host Jeju United at 4:30 p.m. Friday, and Ulsan will bring home Pohang Steelers in their typically heated "East Coast Derby" at 4:30 p.m. Sunday in Ulsan, some 415 kilometers southeast of Seoul.

Pohang are nipping on Ulsan's heels, with 10 points on three wins, one draw and one loss. They also lead the league with eight goals, one more than Ulsan.

Per K League health and safety protocols, teams must dress at least 17 healthy players, including one goalkeeper, to be able to play. Otherwise, their matches may be postponed by at least two weeks.

No other team in the league has reported COVID-19 cases.

Elsewhere in the K League 1, five-time defending champions Jeonbuk Hyundai Motors will try to end their three-match losing skid, when they host Gimcheon Sangmu FC at 7 p.m. Saturday at Jeonju World Cup Stadium in Jeonju, some 240 kilometers south of Seoul.

To shore up their midfield corps, Jeonbuk acquired national team midfielder Kim Jin-gyu on Thursday. Jeonbuk are currently in 11th place among 12 teams with four points from one win, one draw and three losses.

The only club below Jeonbuk, Seongnam FC, will chase their first victory of the season at 7 p.m. Sunday against Incheon United.

Seongnam also kept busy on the player transaction front this week, having signed veteran forward Lee Jong-ho and Colombian striker Manuel Palacios.

Incheon have been one of the season's early surprises, with 10 points from three wins, one draw and one loss putting them in third place. Incheon have often dug themselves early holes and had to play catchup, but they are tied for second-most wins so far this year, only one back of Ulsan. (Yonhap)