Drew McIntyre is currently set to take on Roman Reigns at WWE's Clash at the Castle next month, but recent injury news has cast a shadow of doubt over whether or not this match will take place.

McIntyre reportedly suffered a back injury and has since been pulled from several live events that he was already announced to be a part of. WWE already has the likes of Cody Rhodes, Big E, Rick Boogs, Randy Orton, and several other stars on the sidelines for the foreseeable future.

That being said, if McIntyre is unable to compete in the United Kingdom next month, then there are several current and former stars who could step in.

#5. Seth Rollins already has a storyline with Roman Reigns

Seth Rollins has yet to wrestle at Clash at the Castle as Riddle is still injured and the former world champion has yet to transition to another storyline. Riddle is expected to give an update on the state of RAW tomorrow night, and while Rollins' match may be announced as part of the interview, plans always change.

Rollins is the only star to score a win over Roman Reigns this year with a built-in feud ready to go if WWE is ready to pull the trigger. If McIntyre can't compete, then Rollins is the perfect guy to step up.

#4. Gunther

The current Intercontinental Champion will retain his championship against Shinsuke Nakamura on SmackDown and currently has no challenger for Clash at the Castle. Gunther is undefeated on the main roster and while this will ruin his push when he goes up against Reigns, he can still be considered as someone who can possibly beat Roman.

The match could end in a DQ, allowing Gunther to continue his undefeated streak and could be a storyline that could last for months. Gunther already has one title but can look forward to all the titles for his WWE career as he is a former NXT UK Champion and is also a popular face in the UK.

#3. The returning Johnny Gargano

Johnny Gargano is one released WWE Superstar who is yet to sign with other promotions. Gargano has taken some time away from WWE to celebrate the birth of his son, Quill, and could now make his return to the company under the leadership of Triple H.

Gargano is a Triple H guy and rumors suggest that he could make his return following Vince McMahon's retirement. It would be interesting to see if WWE kept Reigns' opponent a secret and then allowed Gargano to be the surprise star to emerge through the curtain in Cardiff on September 3rd.

#2. Karrion Kross recently put Roman Reigns on notice

Karrion Kross recently made his return to WWE and this past week on SmackDown he put both Drew McIntyre and Roman Reigns on notice. Kross is a former NXT Champion and is expected to step into the title picture following Clash at the Castle, so this could just be WWE fast-forwarding the storyline.

Kross has proven several times with his caliber, and he could easily step in and face off against Roman Reigns in McIntyre's place. The WWE Universe in the United Kingdom would also be handed the gift of Scarlett.

#1. The returning Bray Wyatt could face Roman Reigns at Clash at the Castle

Bray Wyatt is another released superstar who could make his return to WWE following Vince McMahon's retirement. The former world champion is yet to make any kind of move to another promotion, and rumors suggest that he could be on his way back.

Wyatt and Reigns are no strangers to one another and have had some classic matches both as singles stars and as part of The Shield and The Wyatt Family. Much like the above scenario with Gargano, it could be that the company decides to make Reigns' opponent a mystery and then unveil Wyatt's return on September 3rd.