CNN —  

Australian batsman Steve Smith has been ruled out of the third Ashes Test after failing to recover from the concussion he suffered on Lord’s on Saturday.

Smith was hit on the neck by England bowler Jofra Archer and after initially being cleared to return to the second Test, missed Sunday’s play after complaining of concussion-like symptoms.

With only three days between the two Tests, it was unlikely Smith would be cleared to play, and Cricket Australia confirmed on Tuesday he will play no part at Headingly for the third Test later this week.

READ: European Cricket League: Pavel Florin gets backing from Shane Warne

A race to be fit

On Saturday, Smith was initially put through routine tests by Australian team doctor Richard Saw, and the batsman returned to the game before eventually being dismissed for 92.

However, following the close of play on Saturday, Smith complained of headaches and was subsequently ruled out of the remainder of the match on Sunday – Marnus Labuschagne becoming the first concussion substitute in a Test.

Before the 30-year-old Australian had been ruled out of the the third Test, which will start on Thursday in Leeds, he had hoped to be available.

“It’s obviously a quick turnaround between Test matches,” Smith said on Sunday.

“I’m going to be assessed over the next five or six days, each day a couple of times, to see how I’m feeling and how I’m progressing.

Smith leaves the pitch after being hit in the neck by Jofra Archer.

“I’m hopeful I’ll be available for that Test match, but it’s certainly up to the medical staff and we’ll have conversations.

“It’s certainly an area of concern, concussion, and I want to be 100% fit. I’ve got to be able to train a couple of days out and then face fast bowling to make sure my reaction time is in place.”

READ: Steve Smith ‘probably the best Test batsman we’ve ever seen’ as Australia crushes England in opener

A dark reminder

The sight of an Australian batsmen lying prone on the ground having been struck by a cricket ball brought back some troubling memories for Australian cricket.

In 2014, Australian batsman Phillip Hughes died aged 25, two days after being hit in the head by a ball when batting in a domestic match.

Following Hughes’ tragic death, changes were made to further protect batsmen, with stem guards designed and made optional for players to wear on their helmets.

Spectators pay tribute to former cricketer Phillip Hughes.

After initially not feeling comfortable playing with the guards on his helmet, Smith believes he may have to rethink his stance on them following this recent episode.

“I think I, along with a few other players in the team, find it a little bit different, uncomfortable compared to what we’re used to,” he said.

“I feel a little bit claustrophobic when it’s on. I feel like I’m enclosed and not overly comfortable.

“It’s certainly something I need to probably have a look at and perhaps try in the nets and see if I can find a way to get comfortable with it.”

READ: Sledging and the bitter fight for iconic minuscule trophy

The correct decision

Research carried out by Cricket Australia shows that delayed concussion – where symptoms don’t develop until several hours after the initial blow – occur in approximately 30% of cases.

In the second Test at Lord’s, three players were hit on the head and Smith was the only player to suffer a concussion.

Smith lays on the pitch after being hit in the head by Jofra Archer.

And given only around 20% of head impacts in cricket result in a concussion, Alex Kountouris, Cricket Australia’s manager of sports medicine, believes removing a player from the game every time they were struck in the head would be unnecessary.

“The reality is only about one in five or six head impacts end up in concussion,” Kountouris said at a press conference in Australia on Monday.

“If we pulled out every player who had a head impact, we’d be pulling out 80% of players who don’t have a concussion and taking them out of the game. So that would be an overreaction.

“If you look at that game, there were three other head impacts and only Steve had a concussion.

“He didn’t have a concussion at the time (he was hit) so he was allowed to play. If we took him out of the game, we would have been leaving him out of the game for no reason other than what we saw on the field.”

WATCH: Jason Roy on life in and beyond the boundary

Following protocols

Kountouris also said he was “100%” satisfied by Dr. Saw’s treatment of Smith.

“At the end of the day, our doctor pulled him out of day five of the Test match, which was a pretty critical part of the game,” he said.

Visit CNN.com/sport for more news, features, and videos

“Our doctor is an expert in his field, he’s trained to pick up even the minor signs of concussion.

“(He) was brilliant. Everything he did was according to the protocol, he was very thorough, and we know he’s very thorough. We’re 100% happy with what happened over there.”

Australian lead the series 1-0.