Vice President Mike Pence left the 49ers-Colts game after just one series because he was upset after several 49ers players knelt during the national anthem.

Pence, who served as Indiana's governor from 2013-17, has been outspoken about NFL players protesting during the anthem.

"I stand with President Donald Trump and I will always stand for our national anthem," Pence said last month during a rally in Alabama. "I don't think it's too much to ask the players in the National Football League to stand for our national anthem, and I think the people of Alabama would agree."

But some skeptics -- including Colin Kaepernick's mother -- wonder if Pence's early departure was premeditated since some 49ers players have been kneeling before every game dating back to the 2016 season, when then-quarterback Colin Kaepernick first did it.

Pence tweeted this some 90 minutes before kickoff:

Pence left the stadium after this:

Before last Sunday's game, the 49ers took part in a display of unity that included at least 30 players kneeling during the anthem. Other teammates stood behind them and everyone on the 49ers' sideline appeared to have their hand over their hearts.

It also appears Pence was reusing a photo from the 2014 season.

NBC News' Vaughn Hilyard tweets that a staffer told pool reporters that Pence had planned to leave the game early.

And CNN's Kevin Liptak tweets that the operating costs for Pence's plane are more than $42,000 an hour. 

A short time after Pence left Lucas Oil Stadium, President Donald Trump confirmed that his vice president had no intentions of staying beyond the national anthem.

Hours later, the Indiana branch of the American Legion, which has 2.2 million members, issued a statement in response to Pence's decision to leave the game (via IndyStar.com).

"Kneeling during the national anthem and not paying respects to the flag is offensive to many in the veterans community, as many have lost brothers and sisters in arms while wearing the flag on our shoulders to defend those at home. However, it is everyone's right to peacefully protest, as those are the freedoms we are sworn to protect as veterans who have served our nation and continue to serve our communities faithfully."

The statement added that the National American Legion would not boycott the NFL but instead, "We will lead by example, flying the colors of our nation proudly, because it represents all Americans, regardless of race, gender, religion or creed."