Cristiano Ronaldo's return to Manchester United lasted about 45 minutes before things potentially turned tense again.

According to ESPN's Rob Dawson, Ronaldo left Sunday's preseason friendly against Rayo Vallecano before the match concluded after he was substituted at halftime.

Per that report, "He was pictured leaving Old Trafford before the final whistle, with United sources afterward refusing to comment on whether his early exit was sanctioned by manager Erik ten Hag."

Jamie Jackson of the Guardian added: "As half-time neared there appeared a mild contretemps between Ten Hag and Ronaldo during a break in play: The manager seemed to be addressing some positional deficiency which the player shrugged. In a period that petered out this was the last noteworthy sighting of Ronaldo as Ten Hag swapped him for Diallo for the second half."

Per Dawson, Ronaldo has been seeking an exit this summer to secure Champions League football for the upcoming season. Manchester United finished sixth last year and didn't qualify.

Thus far, however, no transfer has occurred, and publicly, the club have maintained that they want to keep the iconic striker.

"We are planning for Cristiano Ronaldo for the season, and that's it. I'm looking forward to working with him," Ten Hag told reporters earlier in July. "I have read [that he wants to leave], but what I say is Cristiano is not for sale; he is in our plans, and we want success together."

Clubs such as Bayern Munich, Chelsea, Atletico Madrid and Ronaldo's first club, Sporting CP, have been linked to the forward in transfer rumors throughout the summer. All could offer Champions League football.

Thus far—perhaps because of Ronaldo's large wages, or United's reported disinclination to sell—no move has materialized.

Ronaldo appeared resigned to the fact that he would be remaining at Old Trafford in a series of social media posts over the weekend:

But Sunday's early departure—at least until United offer clarity on the situation—is only going to re-stoke the flames that Ronaldo is still pushing to leave the club.