The Sky Blues had two massive holes to fill after the departures of Mierzejewski, the Johnny Warren medallist for 2017-2018, and Bobo, who set an A-League season scoring record.

Sydney looked at over 400 overseas players before settling on a couple of replacements.

Last week they signed English striker Adam le Fondre, and on Thursday secured Netherlands international midfielder-forward Siem de Jong on a season-long loan from Dutch giants Ajax.

"We had to make sure we had the right players to fill Bobo and Adrian('s places), they scored 40 (A-League goals last season) between them," Corica said.

"But I believe these two will fit in really well, to the club and the structures that we want to play."

Corica said de Jong and le Fondre would each play around 45 minutes of a practice match behind closed doors next Tuesday.

The new recruits join Serbia playmaker Milos Ninkovic and Dutch defender Jop van der Linden in Sydney's import contingent.

They still have one import place left, but Corica is no rush to fill that vacancy.

"'I'm going to take my time, I'd love to see these two (le Fondre and de Jong) play a few games first," Corica said.

"We have a very good defence, with these two coming into the attack to strengthen that.

"Then we'll see from there, maybe it might be another midfielder or striker. I think it will be more of that than a defender, I think defensively we've got things covered."

Corica said he would use de Jong as both a No.10 and a second striker.

De Jong has thrived in the latter role in the past and believes he can do so again in support of le Fondre, who like himself has Premier League experience.

"I scored a lot of goals being the second striker, so for me hopefully I can do that here as well," de Jong added.