Sweden will face Hungary and Algeria in friendlies over the coming week and while Gyokeres was initially named in his squad, Tomasson has released him due to injury.
Gyokeres is the subject of talks between Arsenal and Sporting, though Tomasson says: "No! He felt a small injury and our medical team was already aware of it and we decided, together, to release him.
"I spoke to Viktor last week. He hasn’t trained much in the last few weeks and was feeling some discomfort because of a small injury.
"I was happy to see him and have him with us in this training camp. It says a lot about Viktor, how much he wants to get involved. We're thinking about it (a replacement) and need to talk more about it. In a perfect world, we have all players available."