Fly-half Finn Russell may be forced home from the British and Irish Lions tour of South Africa with an Achilles tear, says head coach Warren Gatland.

"If he makes good progress we'll assess him going forward. If he's not, then there's a possibility he may go home," said Gatland.

Gatland has called up England fly-half Marcus Smith as cover for Russell.

Wales' Dan Biggar is the only other specialist fly-half in the squad although England's Owen Farrell has made 46 of his 97 Test appearances at 10 and started Wednesday's 54-7 win over the Sharks there.

"Finn's had an injection. It's not a strained Achilles, there's a slight, wee tear in it. That'll keep him out for the next couple of weeks," Gatland added.

"We'll see if we can rehab him and he's going to be in a boot for the next five days. When he comes out of that, he'll have some more treatment over the next five days."

Russell's running, distribution and range of attacking kicks have made him instrumental for both Scotland and club side Racing 92 in recent seasons.

Called up to the 2017 tour as part of a controversial group of six standby players, he made his first start for the Lions in the 56-14 win over the Sigma Lions last weekend.

'We need to be tidier'

Gatland said his team need to tighten up their game from a first-half performance that allowed the Sharks to reach half-time at 26-26 on Saturday, having scored three tries from Lions handling errors.

The tourists, with a man advantage after Sharks' scrum-half Jaden Hendrikse's 46th-minute red card, streaked away to a 71-31 win in the second half.

"We just need to make sure that we are a bit more accurate, tidier and we did that a lot better in the second-half," said Gatland.

"It's what is going to come in the Test matches in terms of the South African team, who will look to come pretty hard, put us under pressure and see if they can catch us behind the gain line with some loose stuff."

Gatland was forced into a late change to his starting line-up with second row Maro Itoje dropping out with a gastric illness.

It was another twist in a week that included an outbreak of Covid in the Lions party, a switch of Saturday opposition after cases in the Bulls camp forced them out of the fixture and several touring players self-isolating in their hotel rooms.

"If anything else happens on the tour that is as chaotic as this week has been, that would probably surprise me," added Gatland.

"There has been chaos. It's then about adapting to that and then changing.

"That's been the mantra. I thought we handled it during the week. I see it as a positive.

"We've just got to go with the flow and react to whatever is thrown at us."