Sale wing Mark Cueto, 25, has been called into the Lions party to tour New Zealand in place of Iain Balshaw.
Cueto has scored eight tries in eight games for England
Leeds full-back Balshaw has not recovered from a torn thigh muscle and it will be up to four weeks before he is able to resume full training.
Cueto said: "This is brilliant news, although it came as bit of a shock.
"I was training this morning when (Sale director of rugby) Philippe Saint-Andre came over and passed on the message that I'd been selected."
Cueto has broken into the England team this season, scoring eight tries in eight matches, and has also reached a European cup final with Sale.
"It's fantastic and the season couldn't have gone any better for me," said Cueto, who many pundits considered very unlucky to miss out on selection for the original party.
"I'll still be playing for Sale in the Challenge Cup final on Saturday."
Lions coach Sir Clive Woodward said he was disappointed to lose the free-running Balshaw.
"Obviously everyone is extremely disappointed for Iain - he is a terrific player," said Woodward.
"But I'm delighted we have someone of the calibre of Mark Cueto to call on."
Balshaw admitted he had been given every chance to recover in time after pulling up during Leeds' 20-12 Powergen Cup final win against Bath on 16 April.
"I was given the best opportunity to try and get right and it was not to be, but that is the nature of sport," said Balshaw.
"I wish Mark good luck for the Tour."
Cueto will now head to Wales to join up with the rest of the Lions party as they prepare for their pre-tour match with Argentina at Cardiff's Millennium Stadium on Monday, 23 May.
They depart for New Zealand on Wednesday, 25 May, with the first Test taking place a month later in Christchurch.