"I just knew as soon as I did it that my hamstring had gone," said Thompson, who was substituted 14 minutes into the second half. "There was no point carrying on. I've had injuries like this before when I've only been out for a couple of weeks, but I have to say this feels worse than that."
At least a month
Tests have confirmed that the player faces between four and six weeks on the sidelines. Celtic will visit Shakhtar on 20 October, with the Ukrainian side, still chasing their first Group F points of the campaign, making the return journey on 2 November. Thompson may be out of both matches but he remains upbeat about his team's chances despite defeats by Barcelona and now Milan.
'Believe in ourselves'
"It's very tough for us now with no points, but we have four games left and we have to take heart from the way we played in the San Siro," the 30-year-old said. "We have to believe in ourselves for these four games."
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