Newly-capped England fly-half Marcus Smith was on Saturday called up to join the British and Irish Lions squad as injury cover for Scotland's Finn Russell.
Smith, 22, who made his England Test debut against the United States last weekend, was due to fly to Cape Town after earning his second cap against Canada in London on Saturday.
A Lions statement said Russell is struggling with an Achilles tendon injury and will be unable to play in any of the three remaining matches ahead of the first Test against South Africa in Cape Town on July 24.
"We're obviously disappointed for Finn, who I think has been outstanding since he came into camp in Jersey, but we are optimistic he'll still play an important role in the Tour," said Lions coach Warren Gatland.
"We have two experienced fly-halves in Owen Farrell and Dan Biggar, so it's a great opportunity for the continued development of Marcus.
"I've been following him closely for the past 12 months and I've been impressed with how well he's matured as a player.
"Finn and Marcus are similar in that they like to play with a bit of freedom, so, for me, it's as close to a like-for-like cover as we can get. We look forward to welcoming him to the group in Cape Town."
The call-up caps a meteoric rise for Philipines-born Smith, who was outstanding for Harlequins in their English Premiership final win against Exeter Chiefs a week before he made his international debut.