Crotty adds to All Blacks injury worries

Crusaders centre Ryan Crotty became the latest injury concern for New Zealand ahead of the British and Irish Lions series.

Crotty left the field midway through the second half in the win over the Highlanders with a rib injury.

And according to Crusaders boss Scott Robertson the injury is likely to keep Crotty out for "several weeks" given the damage to his rib cartilage.

"He's done a rib cartilage, so I think that Steve Hansen will be tucking into his notebook and thinking who's next," Robertson told AAP.

Crotty's good form had led to suggestions he could start in the Test series against the Lions later this month, possibly in a partnership with Sonny Bill Williams.

Steve Hansen's other midfield options include Anton Lienert-Brown and Malakai Fekitoa.