Great Britain look set to play the remainder of their southern hemisphere tour without Luke Thompson and Oliver Gildart, with both picking up serious injuries in the 14-6 loss to Tonga on Saturday night.
Thompson lasted just 12 minutes in the front row before succumbing to a rib injury, while Gildart suffered a dislocated shoulder in the second half.
England coach Wayne Bennett confirmed both players were unlikely to take the field again this year.
"I don't think they will probably play again this series," Bennett said.
"We have got Jake Connor here [as centre cover]. I don't know [if I can bring new players into the squad], I haven't checked.
"I'm happy with the squad right now, we can cover it, we've got the best players in England here, it's not panic time for us."
Match Highlights: Tonga Invitational v Great Britain
Bennett pointed to a lack of patience and an inability to handle pressure at times as leading factors in the loss at Waikato Stadium.
The Lions leaked two tries late in the first half to trail 12-0 and couldn't find a way through the stubborn Tonga line until John Bateman's 70th-minute try.
"I noticed in the Nines [World Cup] last week, I thought there was a couple of things we did in one of the games under a bit of pressure and I didn't like that, and tonight we came out here under pressure again [and did it]," Bennett said.
"I thought we got that out of our game last year and the year before, so we have got to just get that right again.
"We have just got to pick up a bit with our patience and discipline with the football.
"[It's about] being patient, just believing if you stay at it long enough opportunities will come your way.
"Against these teams here, what you saw out there in the first half tonight is what you have got to be able to play week in and week out.
"If we can't do that we can't be the team I know we can be."
Lions captain James Graham, who became just the eighth player in history to reach 50 Test caps in the loss, said despite enjoying few opportunities through the first half his side believed they were right in the contest.
The Lions were forced to make 74 tackles more than Tonga in the first half and spent much of it camped on their own line.
"At half-time we firmly believed we were still in the fight, [but] we knew we had a massive job on our hands," Graham said.
"We spoke about some stuff about how we thought we could get back into the game. It certainly wasn't over.
"I thought the Tongans played with the lead very well in that second half.
"I thought that the first half was a quality half from both teams."
Bennett also expressed concern with the way his new-look halves pairing of Gareth Widdop and Jackson Hastings handled the kicking duties, with a number of instances where they gave up seven-tackle sets with wayward deep kicks.
Bennett has Australia-born former Raiders star Blake Austin in his squad should he choose to make a change before facing New Zealand on Saturday night at Eden Park.
"We fell down a little bit with our execution, being patient, our kicking game," Bennett said.
"Those areas really hurt us in the end … we gave away I think three seven-tackle sets, stuff like that.
"It takes away all your energy to do anything with the football because you're spending so much time defending."