Jankauskas said: "I'm not surprised Craig moved from Hearts for so much money. He is one of the best keepers I have ever seen throughout my career either playing with or against.
"I'm not saying Sunderland are not a big club but I thought Craig would move somewhere better - to a bigger team.
"Craig has a bit of everything, is still very young and once he improves on just a few more details he can become one of the top keepers in the world. It's never easy to score an away goal in international football, especially against someone such as Craig. However, I have scored a couple against him in training!"