Although he impressed in 2021, he was unable to score a single championship point in a Haas car that finished bottom of the constructors' standings.
That first world championship point didn't come until 2022, but Schumacher was largely outperformed by team-mate Kevin Magnussen in that season, and a plethora of costly mistakes marred his season.
Schumacher seeks F1 return
It was ultimately those mistakes and crashes that forced then-team principal Guenther Steiner to react, replacing Schumacher with the more experienced Nico Hulkenberg for the 2023 season.
Hulkenberg and Magnussen have since gone on to form a solid partnership, while Schumacher has been left on the sidelines watching on as Mercedes' reserve driver.
Both Alpine and Haas are yet to confirm their driver lineups for the 2025 F1 season, as are a number of teams up and down the grid.
Schumacher believes this, coupled with his solid performances in the WEC, could make him a candidate for a seat back on the grid.
"My chances in Formula 1 seem to be pretty good so far," said the 25-year-old in an interview with the French news agency AFP.
"For me it is important to return to Formula 1 to show what I can do.
"At the moment, Formula 1 is within reach. I have to make sure that I do not become too confident, that I continue to persevere and make sure that there is a plan B in case it does not work out.
"My plan was always Formula 1, now we have to wait and see what opportunities present themselves to me," he said. "I have decided that I will wait for Formula 1 as long as necessary."