AMES, Iowa (AP) — Iowa State running back Shontrelle Johnson was forced to confront the possibility that he’d never play football again. Now Johnson has bounced back from months spent worrying about a neck injury and is in the best shape of his life. Johnson, who missed much of 2011 following a scary injury in early October, celebrated his return to football on Saturday with the best outing of his career. Johnson rushed for a personal-best 120 yards on 18 carries as Iowa State beat Tulsa 38-23. Johnson and fellow junior James White will split carries on Saturday when the Cyclones (1-0) play at rival Iowa (1-0).