On Sept. 24 in London, more than a dozen Baltimore Ravens players knelt during the playing of the U.S. national anthem before the team's game against the Jacksonville Jaguars. Returning home the next Sunday, the Ravens knelt for a prayer before standing for the anthem. Their home fans booed.

Since then, there haven't been any other on-field protests by the Ravens, who have gone 6-4 over their past 10 games — 3-1 at home — to stay in the AFC playoff hunt. Nonetheless, there have been a sizable number of no-shows in the stands. An estimated 10,000 to 15,000 ticket holders didn't show up for the team's Monday night loss to the Bears on Oct. 15, and the Baltimore Sun made note of the "wide swaths of empty purple seats, particularly in the upper deck" during the Ravens' win over Houston on Nov. 27, again a Monday night.

Playing a prime-time weeknight game might have something to do with those two specific instances. But in a letter sent to season ticket holders, suite holders and sponsors this week, team president Dick Cass said the team's protests might have something to do with their fans not showing up.

"The numbers [of no-shows] are higher, and it is noticeable," Cass wrote in the letter, which was obtained by ESPN. "There are a number of reasons for the no-shows, but surely the one-time protest in London has been a factor."

Cass says the team has taken steps to address whatever concerns the team's fans might have about the protests, with Cass reaching out personally to some who wrote in to complain about the protests.

"We have responded to your concerns about the protest by redoubling the efforts of both the organization and our players to make the Baltimore area a better community," he wrote.

The Ravens play their final home game of the season on Saturday against the Colts and, while the opponent might not be all that exciting beyond the fact that it used to play in Baltimore, the Ravens' playoff push combined with a reawakened offense — they've scored at least 27 points in three straight games after reaching that number just twice in the previous 12 — could get more fans to show up. Secondary-market ticket prices also show signs of a rebound. Before Baltimore's game against the Lions on Dec. 3, the Sun noted that upper-level seats with an $80 face value were going for $29 on StubHub. As of this writing, most upper-deck seats for the home finale are going for at least $50.