Long before Oakland Athletics catcher Bruce Maxwell took a knee in protest during the playing of the national anthem last weekend, Sean Doolittle was giving sincere thought to patriotic displays at baseball games and the surrounding symbolism.

Doolittle, who played with Maxwell in Oakland before being traded to the Washington Nationals in July, is the product of a military family. His father, Rory, served in the Air Force for 26 years and currently teaches aerospace science to high school ROTC students in New Jersey.

During his time in the majors, Doolittle has become a strong advocate for veterans and used his visibility to help them with everything from housing and employment to substance abuse-related issues. In May, Doolittle and his fiancée, Eireann Dolan, wrote a Sports Illustrated op-ed piece to raise awareness of the plight of veterans with "bad paper''-- those who've fallen through the cracks and failed to receive care after less-than-honorable discharges from the military because of alleged misconduct.

Doolittle and Dolan have also taken an interest in lesbian, gay, bisexual and transgender issues, and in November 2015 they hosted 17 Syrian refugee families for Thanksgiving dinner in Chicago. The Athletics nominated Doolittle for the Branch Rickey Award in 2013-2014 and the Roberto Clemente Award in 2016.

During a stop in Philadelphia this week, Doolittle shared his thoughts on the furor swirling around athletes and the national anthem in a conversation with ESPN.com.

Were you surprised when you saw Bruce Maxwell take a knee in Oakland?

Sean Doolittle: "I was a little bit surprised, mainly because it was a young guy that did it -- a guy that still has so much to prove in this league and so much to lose at the same time. [It's harder] for a guy like that to put himself out there. I hope we get to a point whether people agree with him or not, or wherever they fall on the issue, they can respect somebody for standing up for what they believe in.''

What did you learn about Maxwell during your time in Oakland?

SD: "He's a very thoughtful guy. He's really matured a lot as a person and a player over his last couple of years. He had some big league time and got to be around some really good veteran guys in that clubhouse who really helped his development. He has talent, and he's starting to mature and work really well with that pitching staff.

"Bruce is a super nuanced guy. We want to put people in boxes. Words like 'conservative' or 'liberal' or 'Republican' or 'Democrat' have become pejoratives that people use to define and use against other people now. We want to label them before we even get to know them.''

Bruce Maxwell, left, and Sean Doolittle were teammates in Oakland before Doolittle was traded to Washington. Stan Szeto-USA TODAY Sports

There has been a lot of conversation about how NFL and NBA players have jumped into the political fray while baseball players have remained largely silent. Some people point to the racial makeup of MLB rosters or the game's established clubhouse culture. What do you think?

SD: "I have theories, but I don't know. It's touchy.''

Does it strike you that the national anthem is becoming such a flash point for debate?

SD: "A lot of these questions are being posed to people for the first time, like, 'What does it mean to you to stand for the anthem?' I think if you asked 10 people, you might get 10 different answers. You might see one guy standing at attention and other people walking around the concourse buying food or whatever."

What does the playing of the national anthem mean to you personally?

SD: "I came from a military family, so there are a lot of things I think about when the anthem is playing. One thing that bothers me is the way that people use veterans and troops almost as a shield. They say that's the reason they stand and that veterans deserve to be honored and respected during the anthem. But where is that outrage in taking better care of veterans? The most recent statistics say that we still lose 20 veterans to suicide every day.

"If you want to have that conversation, if that's your reason for standing, then let's talk. Let's have a conversation about putting that into action, because they deserve a heck of a lot more than people standing at attention during the flag or giving them discounts on food or hotels.

"It's really nice that we honor them at games sometimes. They'll bring a veteran on the field and he'll get a standing ovation, and that's important. We're in the 16th or 17th year of this war [in Afghanistan], and it keeps a reminder that we are still a country at war. But we need to follow through on those thoughts and actions.''

How are you involved personally?

SD: "My fiancée and I do a lot of work with veterans' issues. Earlier this year, we wrote an op-ed that ran in Sports Illustrated about some of the things we found regarding veterans being wrongly excluded from VA care at a time when they're experiencing a mental health crisis and a suicide epidemic the way they are now. We need to be figuring out ways to expand VA care to take better care of veterans.

"We've worked very closely with three big organizations. We've also gotten closely connected with people in and around D.C. When we were writing the op-ed, we talked to policy makers and policy groups about it. We've learned a lot about veterans' issues and we stay super informed about it. Anytime people use vets and the military as a political football or a prop, it's kind of bothersome.

"The VA works, it really does. For some of the negative press they've gotten in the past few years, when the veterans are able to access it, it really works and saves lives, because they're the ones that are really equipped to handle the unique needs that veterans have."

Do you think there's a distinction to be made between symbolism and action here?

SD: "I don't want it to be a hollow gesture. I think it's a very valid reason to stand for the anthem. But if people are going to point to veterans and use them as the reason, then let's follow through on that.

"If you want to have that conversation, if that's your reason for standing, then let's talk. Let's have a conversation about putting that into action, because [military veterans] deserve a heck of a lot more than people standing at attention during the flag or giving them discounts on food or hotels." Sean Doolittle

"There are a lot of veterans being left out. It takes more than standing for the anthem or 'God Bless America' to stand up for them in a [real] sense. As long as we have a volunteer-only military, a lot of the responsibility falls on the general public to make sure they're getting the care they need when they're done with their service. The veterans raise these questions with Congress and policymakers, but it's going to take the general public to raise their voices in order to really move the needle.''

Some people say that athletes who kneel are disrespecting veterans and their service. Others maintain that veterans have fought to give people the right to peacefully protest in such a manner. Can you understand both arguments?

SD: "I worry sometimes in this country that we conflate patriotism exclusively with love of the military and militarism and the strength of our armed forces. That's not the only way that you can be patriotic.

"People draw a direct line between the national anthem and the military, or patriotism and the military. But there are a lot of things that we're not doing for veterans.''

Have you seen any positive changes since you've been doing advocacy work for veterans?

SD: "It's getting better. [Veterans Affairs] Secretary [David] Shulkin, who was appointed last year, is doing a good job. But it's almost like we have to capture some of the momentum so that we don't lose any of that progress. He said his priority is bringing down the suicide numbers and reducing that rate.''

Can the current debate be a "teachable moment"?

SD: "I think it's important to realize that the players who are protesting aren't protesting the anthem. They're not protesting the flag. People kind of move the goalposts on them and try to tell them what they're protesting. But as they keep saying, that's not what they're protesting.''

As someone who stands for the anthem, what's your response to athletes who kneel?

SD: "I think American democracy is strong enough to have that conversation. I think my patriotism is strong enough to not be offended when somebody takes a knee during the anthem. That's not something I take personally. It's something that makes me want to reach out to that person and have a conversation with them and say, 'Let's talk about some of these issues. Tell me about certain things that have caused you to take such a stand.'

"I want to have these conversations with guys like Bruce Maxwell and guys in other leagues, and maybe someday we can get to a point where we give them a reason to stand, and they're proud to stand along the other guys that are standing.''