With Serbia's opening Group D game against Ghana in Pretoria on Sunday approaching quickly, Serbia's head coach Radomir Antic has inconsistence and inexperience to choose from among his three shot-stoppers.
Zalad, a former goalkeeper who plied his trade at Partizan Belgrade and the Turkish first division, said first-choice Vladimir Stojkovic needed to rediscover his best international form to avoid letting down the team.
"Stojkovic has played below par at club level since he moved abroad from Red Star Belgrade in 2006 because his choice of clubs has been unfortunate and detrimental to his career," Zalad told Reuters.
"It's like taking a wrong turn: when the first one is wrong every next turn is wrong too because it's a chain reaction and it's difficult to get back on track.
"But Stojkovic has a strong character and we hope the World Cup brings the best in him as was the case in qualifying where he was outstanding."
DIFFICULT YEARS
Stojkovic has endured four difficult years at club level after coming to the fore at Red Star and his loan spell at Premier League side Wigan in the second half of last season was littered with howlers.
In contrast, the 26-year old goalkeeper has been remarkably consistent for Serbia since his international debut in 2006 and he has remained an automatic starter under four coaches despite lack of first team football at club level.
However, two soft goals he conceded in Serbia's 4-3 win over Cameroon in their final warm-up may prompt the team's coaching staff to look at other options, especially after third-choice Andjelko Djuricic shone in Wednesday's practice.
"My job is to make sure that all three goalkeepers are in top form throughout the tournament because any of them can be called upon at any point in time," Zalad said.
"They are all working hard and it's now up to Antic to pick the starter, my guess is that it's going to be Stojkovic because he is the most experienced and his form has improved throughout the build-up.
"As far as the Cameroon game is concerned, we'd rather see Stojkovic make blunders during the warm-up games than when the real thing starts."
Despite Stojkovic's rollercoaster form, he is likely to stay ahead of Djuricic and Bojan Isailovic in the pecking order.
Djuricic has played only 45 minutes for Serbia in a 1-0 warm-up defeat by New Zealand while Isailovic's four caps have also been limited to friendly matches.
