The 24-year-old struggled to establish himself at Sporting having scored just three times and provided four assists in his 28 appearances on loan last season.
Campbell confirmed to the Portuguese media last week that he would be returning to London after a season in Lisbon. He was however positive about his time in Portugal saying he felt he had learned from the experiences playing in the country and was satisfied with the season, despite his lack of starts:
“I am 24 years old, I have been in several leagues and it has helped me to accumulate experience to become a better player and a better person. So I am satisfied.”