Carlisle United boss Chris Beech said his decision to sub a substitute at Leyton Orient was because a back problem had flared up again with Ethan Walker.

The Preston loan attacker came on in the 63rd minute in United’s 3-2 win but was replaced in the 86th minute.

Beech said an injury issue was the reason he withdrew Walker after a 23-minute outing from the bench.

The Blues head coach said: “After training on Friday he rang Gav [Skelton, assistant boss] to say his back spasmed a little bit.

“Ethan assured us [on Saturday] morning he felt a bit better – he felt ok in the warm-up and he’s been a spark coming on for us in games. The game looked like it needed one at that point to take it up a notch.

“But obviously his back’s not great, he didn’t feel quite comfortable, and when I see the opposition full-backs cross that football, I want to protect our result.

“At the time we’re drawing a game, I want to protect the result while working hard to get our winner – that’s all that was.”

Walker’s issue was one of two injury problems Carlisle suffered in the game.

Striker Offrande Zanzala limped off in the 22nd minute, just minutes after he had seen a penalty saved by Os keeper Lawrence Vigouroux.

Beech said: “It’s just the hamstring that he’s just tweaked again, [he said it happened] in the incident of gaining the penalty.

“But strikers being strikers, he probably thought won’t have to do much running and take it.

“But he’s had to come off. Sometimes you could say why take it, but often when your adrenaline’s running hard, and you’re running hard in a game, you don’t know at that point.

“He felt something, but if everybody gave up at the first thing they feel, there would be nobody on that pitch.”

Beech was without central defenders Rhys Bennett and Rod McDonald in London and said the former will not be risked in Carlisle’s last game of the season against Walsall at Brunton Park next Saturday.

"Rhys has some scar tissue on the knee, because at Cheltenham he was pushed and he sat right back on it," Beech said.

"It opened the knee ligament up a bit.

"If he declares himself fit when he isn't, I just don't want to risk him having a future. He definitely won't be available next Saturday."

Beech said he "hoped" McDonald could be fit after a dead leg, but said of Saturday's centre-halves: "I did think Nick [Anderton] and Aaron [Hayden] were excellent.

“They played some good passes but it incorporated individual mistake. But they both responded with great character to make sure they finished on the winning team, I’m pleased for both of them.”

Beech also kept faith with Magnus Norman in goal for a second game, with regular No1 Paul Farman again on the bench.

“No big deal, Paul’s been brilliant, Magnus was excellent Tuesday [at Cheltenham] – simple as that really,” he said.

While midfielder Dean Furman missed a further game with injury, there was again no place in the 18-man squad for Gime Toure.

The attacker has been out of favour for Carlisle’s last two games.

Beech said: “You look at the bench, the output of that, you want to give people opportunity, and I’ve just said that to people – I’ve given opportunity to everybody this season, people have had opportunity to stake their claim but there’s no big deal in that.

“I picked a squad to come here and beat Leyton Orient and they have.”