Australian fast bowler Ryan Harris looks unlikely to start in the upcoming third and final cricket Test against Sri Lanka after scans revealed a hamstring strain. Harris had complained of a stiff right hamstring on the last day of the drawn second Test in Pallekele on Monday and underwent scans when the team drove to Colombo on Tuesday afternoon. Australia, leading 1-0 in the three-match series, are unlikely to risk Harris in the final Test starting at the Sinhalese Sports Club on Friday, although the bowler himself is keen to play. "I want to play as much as I can but I know I am a risk," Harris, nicknamed 'Rhino' for his burly physique, told reporters after the team's training session on Wednesday, which he missed. He said he will leave the decision to captain Michael Clarke and the team management, adding: "If Michael is happy to take me in with a slight risk, I will give it 100 percent in what is a pretty big game. If not, I will sit out and do as I am told." The hamstring strain is the latest setback for injury-prone Harris, who has been battling a chronic knee problem since his debut last year. "It's disappointing because I have done a fair bit of work to be strong again and something minor like this has upset it," he said. The 31-year-old has been Australia's most successful bowler in the series with 11 wickets, including a five-wicket haul in the first Test in Galle that fashioned Australia's 125-run victory. Harris took six wickets in the second Test, but heavy rain in Pallekele frustrated Australia's bid to record a series-clinching victory. If Harris is declared unfit to play, Australia have two other seamers, Peter Siddle and James Pattinson, to choose from. Neither has played in the series so far.