Citing the “unique and difficult challenges” brought about by the COVID-19 pandemic, KU officials announced Tuesday night that the first game of a six-game series — scheduled for Dec. 12 in Kansas City, Mo. — now will be played during the 2026-27 season, on the back end of the agreement.

The series now will begin on Dec. 11, 2021, at Allen Fieldhouse during the nonconference portion of the 2021-22 season, and the two teams will alternate home games during the first four seasons of the series before playing neutral-site games at T-Mobile Center during the 2025-26 and 2026-27 seasons.

“I was excited about beginning this series with Missouri again,” KU coach Bill Self said in a news release announcing the move. “However, it is in the best interest of both of our schools and especially our fans to push this back a year. This rivalry goes back a long way, and we want our fans to be able to witness it again in person. So, delaying it a year was an easy decision.”

Kansas Athletic Director Jeff Long said in the release that the new start date for college basketball — from Nov. 10 to Nov. 25 — led to Kansas redoing its nonconference schedule and left a handful of games vulnerable.

KU has not yet released any portion of its 2020-21 schedule, but reports have indicated that the Jayhawks will play Boise State on Nov. 25 in Game 1 of the two-game Wooden Legacy tournament in Orlando and that KU will face Kentucky in the Champions Classic on Dec. 1 also in Orlando.

Sources close to the situation also recently confirmed a report from CBS Sports that indicated that the Jayhawks will play two Big 12 Conference games in December, a couple of weeks earlier than conference play typically begins.

“With the Big 12 conference games also being adjusted, and the likelihood of only 10-20% of fans permitted to attend the (Dec. 12 KU-MU) game due to the pandemic, it became clear that we should delay the series,” Long said. “We appreciate Missouri agreeing to the delay and we look forward to renewing the Border Showdown at Allen Fieldhouse on December 11, 2021 with a sellout crowd.”

Although Kansas and Missouri have faced each other in both volleyball and softball on a couple of occasions since Missouri left the Big 12 Conference for the SEC in 2012, those came in the postseason and were not scheduled by either school.

Technically, it was the Kansas baseball program, in the spring of 2012, that played the final scheduled game with the Tigers. But by far the most notable final meeting came earlier that year, when the KU basketball team came back from 19 down in the second half to win an epic game at Allen Fieldhouse.

KU and Mizzou did meet in 2017 in an exhibition game in Kansas City, Mo., that raised more than $2 million for hurricane relief. The Jayhawks won that game, 93-87, at the outset of what became a run to the 2018 Final Four.

The Kansas-Missouri basketball series, which was known until 2012 as the longest continuous series west of the Mississippi River in college athletics, dates back to 1907, when the Jayhawks and Tigers met on back-to-back days in Lawrence on March 11-12, both Missouri wins. Those contests were the first of 269 meetings between the border rivals over the next 105 years, with the Jayhawks building a 174-95 edge in the all-time series.

Kansas is 89-33 at home against Missouri, including a 42-14 mark in Allen Fieldhouse, and owns a 65-53 edge in games played in Columbia.

The Jayhawks own a 20-9 all-time advantage in neutral-court games.