Joel Stransky says not playing regular-season matches against New Zealand teams will count against the Lions in their Super Rugby semi-final at Ellis Park on Saturday.
The Lions topped the overall log this year, but did so without playing any of the Kiwi franchises.
On Saturday, Johan Ackermann's men will face New Zealand opposition for the first time in 2017, in the form of the champion Hurricanes.
The Lions lost 20-3 to the Canes in last year's final in Wellington, and were thrashed 50-17 at Ellis Park during the regular season.
Stransky fears the Lions could lose again on Saturday.
'I'm really concerned they haven't played any New Zealand teams yet,' the former Bok flyhalf told Radio Sport.
'The Sharks were very clever in the way they applied pressure and went about things and the Hurricanes would certainly have learned from that.
'[Hurricanes assistant] John Plumtree would have studied that inside out, knowing the Sharks and Lions very well and the Hurricanes coaching team are very smart.
'They'll have picked out what Sharks did really well where weak points are and I've got this horrible feeling Hurricanes might come here and win … it's going to be a really tough game for the Lions.'
'[The Stormers] came unstuck on the weekend against a Chiefs team who were good but not outstanding. That for me sums it up for the South African teams.
'If you're not playing the best teams, like the Chiefs, Hurricanes, Crusaders and Highlanders, you're not testing yourself.
'You're not stepping up when it matters and when you do have to play those teams in a one-off knockout game it's going to be very tough to catch up with the pace of game, style of play and different set of pressure that comes your way.'
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