Great request, but should only materialize when a player becomes a key veteran for the team.
That said, this is another area where EA has lapped SDS. You see, in Madden NFL 27 and NHL 27 titles, this option is already in those two games. When you become a captain in either game within their avatar offline modes, you can help shape who the team pursues in trade deadline deals. Madden takes it further than NHL because in the early offseason it also lists the available free agents and lists the team's cap space.
So, you can go through the list of FA's and check those whom you recommend the team pursues. And thing is, the team may well go in that direction.
So, when I say that SDS is way behind their rivals in immersion, this is but one concrete example of that reality, among many other such examples.