Steve Smith has reportedly been ruled out of the remainder of the second Ashes Test after failing concussions protocol.

According to the Mirror, Smith will not be allowed to bat in the second innings of the second Test after he was struck in the head by a bouncer from England paceman Jofra Archer.

The Australian star was forced off the wicket midway through his innings yesterday afternoon after being struck in the neck/jaw area.

Smith did eventually return to the wicket later on in the day before he was dismissed by Chris Woakes LBW on 92.

The Mirror are reporting that he underwent concussion tests this morning ahead of the final day at Lord's, and he's been told he can play no further part in the remainder of the match.

This now leaves him in serious doubt for the third Test which starts at Headingley on Thursday.

Smith was once again frustrating the English bowling attack, hitting yet another half century and then looking comfortable on his way to yet another Test match century.

However, he was then hit on the arm by a vicious bouncer from Archer, which left him needing attention from the medics.

After receiving padding for his arm, his innings continued.

Later on in the day, though, the serious incident took place, as Archer delivered a rapid ball that bounced up and connected with Smith's head.

He immediately dropped to the floor and England fielders were quick to rush to his aid. Medics from both teams also ran onto the field to come to the aid of the batsman.

The images were pretty concerning for Smith, especially given the history of cricketers being hit in the head by bouncers.

Luckily, he got to his feet and walked off the field only to return later to continue his spell.

It was very noticeable that he wasn't the same, and he was eventually trapped LBW.

Sky Sports commented on Smith's health this morning during the final day, and the Australian reportedly woke up this morning feeling dizzy and unwell.