Marcus Rashford was Ten Hag's mainstay player last season and his contribution was extraordinary in helping Manchester United attack. Marcus Rashford scored 17 goals in 35 Premier League appearances last season and he scored 6 goals in the Europa League in 9 matches. That's a fine goals stat for a striker who in the previous season only scored 4 goals in the Premier League in 25 appearances.
Ten Hag managed to turn Marcus Rashford into an important striker in his squad last season, so he deserves a contract extension until 2028. But then, I think Ten Hag also needs to bring in another striker to push more power in attack. Don't know who, but it's a priority they should think about.
Rashford has always been a mainstay at Manchester United, whoever the coach is he is always ahead but sometimes injuries get in the way like now Rashford is injured and can not be determined when he can play. Actually Manchester United have a lot of players in the squad for the Right Winger position they have 5 while for the Left Winger position at least 4 players there so I'm not sure if they still need additional players especially the players on the front line.