Four-time Olympian Shalane Flanagan will miss April’s Boston Marathon due to a back fracture, the Boston Athletic Association announced.

“I have shed a lot of tears this past week,” Flanagan wrote on Instagram. “I’m injured and have to withdraw from my hometown race, my favorite race, the race that means the most to me, The Boston Marathon. I fractured a bone in my low back training through a stretch of snowy weather in Portland, OR. I’m heartbroken that I will not get the opportunity to test myself against the greatest runners on the planet. I consider myself a very fortunate person. I’ve had more good than bad in my career. But I can’t lie, this stings. One thing I know, is that marathoners are used to suffering and overcoming challenges. We come back to try again….and again.”

The injury sounds severe as she will be forced to miss about four to six weeks of training to recover.

Some quick thoughts:

Shalane Flanagan’s bucket list item remains for now

Before the 2016 U.S. Olympic Marathon Trials in Los Angeles, Flanagan said her immediate goal was to make the Olympic team but one of the last things remaining on her bucket list was winning the Boston Marathon. 2017 would’ve marked her fourth run on the course. Her best placing was a fourth place showing in 2013 in 2:27:08, when she was still training with Kara Goucher. Her best time and the current American women’s record on the course is her 2014 sixth-place run in 2:22:02, where she attempted to take the race essentially wire-to-wire but was swallowed in the late stages of the race. She last raced Boston in 2015, when she ran 2:27:47 for ninth place. She did not run Boston in 2016 as it was too close after Los Angeles for any trials participant to recover and race. Flanagan will turn 36 in July and with no world championships next year, she could give Boston one last shot.

Who is now the American favorite?

Desi Linden, who took seventh and finished just one spot behind Flanagan in Rio, has the second-fastest Boston time by an American woman as she ran 2:22:38 to just get edged out by Kenyan Caroline Kilel for the win. Linden beat Flanagan at the Trials and took fourth in 2:25:39 in Boston as the top American woman. Linden could still contend for a podium spot as she now moves to fourth on the list of the elite women, if we rank them by personal bests.

Only Gladys Cherono of Kenya, 2:19:25 (Berlin, 2015); Edna Kiplagat of Kenya, 2:19:50 (London, 2012); Buzunesh Deba of Ethiopia, 2:19:59 (Boston, 2014) CR and Atsede Baysa of Ethiopia, 2:22:03 (Chicago, 2012) have faster personal bests.

On the men’s side, if Galen Rupp has made a full recovery from his plantar fasciitis that knocked him out of the Houston Half Marathon, then he could be favorited to win the men’s race.