Track great Michael Johnson is recovering from a mini stroke last week. The 50-year-old former sprinter said on Twitter he “rather surprisingly” was stricken with a transient ischemic attack. Johnson, a four-time Olympic gold medalist, wrote that he has been “cleared of any heart issues.” ... English welterweight Amir Khan had to get off the canvas to continue his comeback with a points win over Samuel Vargas in Birmingham, England. In his second fight since a two-year absence, Khan was knocked down late in the second round. But the 31-year-old Khan (33-4), a former world super lightweight champion, earned a unanimous points victory.