Tests have cleared Protectionist of serious injury but the stayer will have to be reassessed before starting a campaign aimed at winning back-to-back Melbourne Cups.

Connections feared the horse's career might have been over when he pulled up extremely sore after a disappointing performance in the Sydney Cup on Saturday.

He underwent scintigraphy scans this week, a procedure which identifies `hot spots' on the body, and the results showed Protectionist had bruising on his left knee but no chips or breaks, much to the relief of trainer Kris Lees.

"It's good considering what we thought it was going to be this time yesterday," Lees said.

"He got down on his bumpers really badly (in the Sydney Cup) so he could have hyperextended (his knee) which caused some bruising and he did have some localised swelling behind his knee."

Lees said Protectionist would be spelled for six to eight weeks.

The horse will then be checked to determine whether he pursues a spring campaign.

A shot at back-to-back Melbourne Cups will be the main mission for Protectionist if he can prove his fitness.

"If we didn't think he was ready to do that in the spring we would give him a long spell," Lees said.

The Newcastle trainer also confirmed top mare Lucia Valentina had been sent to the spelling paddock after running in the Queen Elizabeth Stakes.