Pro football players throwing in the towel is nothing surprising these days, especially with the awareness and worry of concussion affects at DEFCON 1. But deciding to up and quit, during halftime, in a game that you were playing in, most certainly is.

And that's exactly what Buffalo Bills cornerback Vontae Davis did on Sunday.

Davis released a statement after the game saying, "Today, on the field, reality hit me fast and hard. I shouldn't be out there anymore." Here's his entire statement:

Davis endured nagging injuries the last several years and said he just didn't feel right during the game, one in which the Bills were getting walloped by the San Diego Chargers by halftime, 28-6. So, Davis pulled himself out of the game and told the coaches he was done. 

Sure, we've all heard stories of people that call it quits, on the spot, after an event at work. But was that event televised nationally or did that person forfeit nearly $5 million dollars of salary in so doing, as is predicted Davis will?

Some say they understand what Davis did, that we all can understand it. His teammates disagree. Bills linebacker Lorenzo Alexander had this to say about Davis' abrupt retirement after the game (edited for brevity):

"Never have seen it ever. Pop Warner, high school, college, pros. Never heard of it. And it's just completely disrespectful to his teammates. He didn't say nothing to nobody. I found out going into the second half of the game. I don't have nothing to say about Vontae, I'm going to give him a little bit more respect than he showed us today, as far as quitting on us in the middle of the game."

I think Davis should at least have had the courtesy to finish out the game he was in, talk to his teammates afterward, and then do what he needed to do. Given the dangers of playing in the NFL, no one could begrudge him that.

It got me thinking, great leaders often need to maintain relationships and support colleagues. So how can you be a great teammate? By doing these seven things:

1. Play your position and be in position to play.

Not just "work hard, play hard", this is about knowing what to work hard at. This means knowing what your "role in the assembly line" is and being prepared and feeling accountable to deliver it with excellence--then reliably doing so, especially in the clutch. 

After giving your responsibilities everything you've got, don't let that be all you give. Save some mental energy and capacity to unwind and enjoy with the co-workers you've been busting tail alongside.

2. Give them 10 percent more.

This goes beyond the first point. You know how it feels when you see a waiter, sales clerk, or flight attendant give that extra effort. You feel important, cared for and want to reward their dedication. You immediately sense you can count on such people.

It's no different with your co-workers. Making a conscious effort to put 10 percent more into what you're helping them with, or into your own work, will be noticed by a factor of ten.  Camaraderie will follow.

3. Spread positive gossip.

Get caught talking about your co-workers, in an upbeat way. Plenty do the opposite. Swim upstream. Brag about how good they are to their boss or share positive stories about them at a team meeting, for example.

4. Invite their gifts in.

Create an environment where others feel comfortable, appreciated, and warmly invited to share their unique talents. They'll return the favor.

5. Openly and subtly have their backs.

Help your compatriots solve a circumstance, look for ways to help and support them, share information they could benefit from, accept their imperfections, and be their fiercest advocates.

Just as powerful, look for those quiet moments, when no one else is looking, where you can help create a positive impression of teammates or help move something forward that's important to them, like a project or their career.

6. Exude care and compassion.

Care enough about your cohorts to be interested in and actively listen to them. Care what they think, notice and remember things about them, root for them and enjoy their successes, help them grow with thoughtful feedback, and do something nice for them from time to time. Make it OK for them to be vulnerable and make mistakes.

7. Bring energy and inquiry. 

Be all-in and exude positive, authentic energy that will draw teammates in. Be inquisitive about your teammates and about how you can contribute more value to the team.

Before you call it quits, ensure you've called in everything you can to be a memorable teammate along the way.