sentences:  In addition, Mattingly had tied Dale Long's major league record by hitting home runs in eight consecutive games (record later tied again by Ken Griffey, Jr., of Seattle in 1993), as well as stroking an extra base hit in ten consecutive games.Mattingly had a record 10 home runs during this streak (Long & Griffey had eight of them).In June 1987, it was reported that Mattingly injured his back during some clubhouse horseplay with pitcher Bob Shirley though both denied this.