STEVE Borthwick has refused to be drawn on Owen Farrell's chances of beating his thigh problem in time for the first British and Irish Lions Test.

Farrell will miss Saturday's Maori All Blacks clash in Rotorua after suffering a "grade one" quadriceps strain, that general medical opinion suggests can take seven to 10 days to heal.

That could leave Farrell a serious doubt for the first Test against the All Blacks in Auckland on June 24 - but Lions assistant coach Borthwick has refused to offer any definitive progress report.

"He didn't train today, he's had a grade one muscle strain," said Borthwick of Farrell's injury.

"The medical team will take great care of him. Hopefully he'll be back on the field as soon as possible.

"When exactly it happened, I can't tell you. It was felt yesterday, dealt with immediately, and he went into recovery protocols straight away."

Asked if seven to 10 days would be a reasonable time frame for Farrell's recovery, Borthwick said: "I certainly don't go by that.

"I listen to our medical team who are far more qualified than I am. He'll be back as quickly as he's fit and able."

Asked if the Lions would suffer a blow if Farrell were to miss the first Test, Borthwick continued: "You deal with the hypothetical and I'll deal with what the facts are. He'll be back as soon as he's fit and able to be back.

"Owen is an incredible professional. We've got a fantastic medical team and he'll be back on the field as soon as he's physically able.

"They'll monitor that on a daily basis, and we'll get updates on a daily basis.

"If you want any more detail on that you'll have to ask (head coach) Warren (Gatland) when he's next up."

Asked if Farrell's injury scare has dented the Lions' squad morale, Borthwick said: "No. Things happen in professional sport, we just concentrate on getting on with things."

All Blacks boss Steve Hansen has claimed the Lions will call up five or six players to bolster their squad for the second half of the 10-match New Zealand tour.

The Lions have never suggested they would add to their ranks, and Borthwick insisted there are no additions imminent.

The England coach also claimed the Lions will not pay any heed to New Zealand boss Hansen's comments.

"I think if there's a situation where call-ups are going to happen for any player that will be dealt with at the appropriate time when an announcement's to be made; and right now there's no announcement," said Borthwick.

"I'm concentrating on Saturday's game."

Asked if Hansen's comments were frustrating to the Lions, Borthwick added: "I'm not giving what anyone else is saying a second thought. I'm concentrating on our team.

"I'm concentrating on coaching the team as well as I can.

"I think I've been hugely impressed by the leadership of the players, all the players in how close this group is.

"All the players have worked hard to ensure it's a tight, socially cohesive group.

"If and when there's any situation for an announcement (on players to join the squad), that will come then.

"Right now there's no announcement and I'm concentrating on the game on Saturday."