The winger scored one goal at the finals, a cracking volley to open the scoring against Argentina in Group D, and otherwise impressed throughout the tournament.
United are among Rebic's possible suitors, while Sevilla and Tottenham have also been mentioned as possible summer destinations - and the player himself affirmed that his agent has fielded calls from other clubs.
When asked about Jose Mourinho's apparent interest over a possible €50 million (£44m/$58m) move, Rebic told Goal: "I am obviously glad to hear and read about how many big coaches and clubs are asking about me. Honestly, I think I deserved it!
"I had a great World Cup and an even better club season with Eintracht. Yes, I know there are concrete offers, I keep in regular contact with my agent.
"I'm glad I proved that everyone can count on me, but as I said there is enough time left until transfer window closes."
Rebic added that he was not anxious about his future, after Frankfurt director Fredi Bobic affirmed the club were yet to receive an approach for their star man .
"Transfer offers? It's still early for those stories, the transfer window is open for almost another month," he said.
"When I moved to Fiorentina the transfer was completed on August 29, and my transfer to Eintracht was done on August 31.
"Most transfers are done during the last days [of the window] so that is when my situation will be more clear. Now I am an Eintracht player and I have returned to training with my team."
The Croatia star also looked back on his nation's thrilling World Cup run, and admitted the full extent of their achievement was yet to sink in.
"We are still not aware of what we did in Russia," he added.
"Only a few days after the final I watched the match and saw the way we conceded the first goal, then the second and it was not easy to get back into the match after such obvious refereeing mistakes.
"But we gave our best and have no regrets."
United, meanwhile, are looking to add to their squad before the transfer window closes in England on August 9.
Mourinho again expressed his concern at the club's summer transfer business prior to his side's pre-season defeat to Bayern Munich, insisting executive vice-chairman "knows what I want" .
The Portuguese warned the Red Devils could be in for a difficult season if they don't make any further improvements to their squad, although the club could now attempt to finalise a deal for Toby Alderweireld after pulling out of a move for Yerry Mina .