Speaking in an interview with German magazine Kicker, the 30-year-old said: "Right now you can only say that Goretzka's coming to Bayern, but you can't say whether, how or where he'll play. Obviously he's a classy player; he wouldn't be coming to Bayern otherwise. But we'll just have to wait and see."
Watch: All of Vidal's Bundesliga goals and assists in 2017/18
Goretzka's move to the Bundesliga champions from Schalke was confirmed in January, leading to speculation that the 22-year-old Germany international would take Vidal's place in the side.
However, the Chile international is evidently confident of retaining his starting spot, having held down a regular berth this season even after the arrivals of fellow central midfielders Sebastian Rudy and Corentin Tolisso in summer 2017.
Indeed, Vidal has made more appearances (22) and played more minutes in the Bundesliga this season (1366) than any of his direct rivals in the centre of the pitch, including the aforementioned duo as well as Thiago, Javi Martinez and James Rodriguez.
He is also eager to extend his stay at the club beyond his existing contract, which expires at the end of the 2018/19 season: "Whether or not I stay depends on the people here at the club, but we're on the right track. Right now I'm only thinking about our upcoming games."
Next up for Bayern is the return leg of their UEFA Champions League last 16 tie away to Besiktas, with Jupp Heynckes' charges holding a 5-0 advantage from the first leg – a match which Vidal also started. "We want to win every game, including this one in Istanbul," he said. "We're going there to do our job and to get into the quarter-finals with another win."