In 2015 the MLB had the first female baseball player, French shortstop Melissa Mayeux, recognized on the league's international registration list. On Tuesday the Oakland Athletics made more headlines after they announced the hiring of the first female coach in MLB history.

Justine Siegal, who also became the first female to serve as a coach for a professional men's baseball team back in 2009 when she was with the Brockton Rox, will now join the Athletics as a guest instructor for the team's 2015 Instructional League, which will take place from Oct. 4-17 in Mesa, Ariz., according to the club's website.

Siegal also became the first woman to throw batting practice for MLB teams when she pitched to the Athletics, Indians, Rays, Cardinals and Mets in the spring of 2011.

"We're thrilled that Justine will be joining us for Instructional League," said A's assistant GM David Forst. "She brings with her a wealth of knowledge and expertise from years of playing, coaching, and teaching the game, and all of our young players stand to benefit greatly from her time in camp."

Siegal has loved baseball her whole life, dating back to when she would attend Cleveland Indians games as a kid. Although she was denied a chance to play on her high school's varsity baseball team, Siegal has pursued her passion by participating in men's baseball leagues ever since. She is also the founder of Baseball For All, which "fosters, encourages, and provides opportunities for girls to participate in baseball."

"This was a great moment," Siegal told Alyson Footer of MLB.com. "I feel qualified for this job. I have a lot to learn, but I feel I've worked my way up the ranks. I can't stress enough how thankful I am for the opportunity."

Siegal also described what her duties will be when she starts in October.

"There's field time and classroom time. That's a normal part of the routine. Throwing batting practice, hitting fungos, a little bit of a classroom time. ... I'll do whatever they need."

There's also a chance Siegal breaks more barriers once her stint at the A's Instructional League concludes.

"There is a chance that the opportunity could turn into a full-time coaching job with the organization at some point," writes Susan Slusser of the San Francisco Chronicle. "The A's do not have their minor-league coaching assignments set for next season, so they do not yet have an idea about potential job availability."

You never know. Once you have a foot in the door the opportunities are endless. Siegal is headed down that road and she could also become the first ever female coach on a minor-league team.