Mariners' top prospect Jonny Farmelo, who is ranked No. 78 on MLB Pipeline's top 100 and No. 54 on Baseball America's top 100, is set to be sidelined for 4-6 weeks due to suffering a stress reaction in his rib, according to Mariners General Manager Justin Hollander. Farmelo, 20, suffered the stress reaction in his rib from swinging a bat.