Henderson came off at the interval after suffering the injury when he landed awkwardly during the first half of Liverpool's 1-1 draw at Borussia Dortmund in the Europa League quarter-final first leg on Thursday.
A scan on Friday showed the 25-year-old sustained lateral collateral ligament damage which, under normal circumstances, can lead to anything up to a three-month layoff.
However, a statement on Liverpool's website said Henderson's problem “appears to be less serious and providing all goes well with the midfielder's recovery programme, the time out of action could be limited to between six and eight weeks”.
The Reds said Henderson does not require surgery on the injury, but he will still miss the rest of Liverpool's season even if they reach the Europa League final on May 18, and that puts his participation in England's Euro 2016 campaign in doubt.
Given an eight-week injury lay-off would rule Henderson out of his country's three warm-up friendlies against Turkey, Australia and Portugal ahead of the European Championship, the former Sunderland player will have little time to prove his fitness to England manager Roy Hodgson.
Hodgson is due to name his 23-man squad for the tournament in France on May 12 and has previously admitted a reluctance to include players who are not match fit. – AFP
Original source: Henderson doubtful for Euro 2016