Spurs captain Hugo Lloris missed the last Premier League outing and he is still ill.
United travel to Wembley to play Tottenham on Wednesday night when the Chilean will expect to make his first league appearance against familiar foes.
United manager Jose Mourinho, whose second placed side are 12 points behind leaders Manchester City, clearly agrees with Herrera about Sanchez's catalyst qualities. If - I'm saying if, if, if - that is true and Zlatan wants a future in another club, in another country, we are here to help and create conditions for that to happen, not to make his life hard.
"We have recently been advised about all your wonderful dedication to Manchester United." the letter read. Only against Aston Villa (85) and Arsenal (82) has it claimed more league wins than it has against Spurs (80).
In the last six seasons, at least one of the meetings between these two sides has featured over 2.5 goals - a market that can be backed at 11/10 (2.10) - which bodes well for this clash as the reverse ended 1-0 to Mourinho's men.
However, Tottenham are unbeaten in their last five games in the Premier League and haven't lost at Wembley since a 2-1 defeat at the hands of Chelsea back in August. His ability to create openings for Harry Kane, and to conjure something out of nothing for the north Londoners with his set-piece delivery and eye for a pass could be the difference. Right now they are two points back of the final UEFA Champions League group stage berth.
"Zlatan is in the previous year of his contract".
After learning that 94-year-old Manchester United fan Fredrick Schofield had been going through a hard time, Jose Mourinho made a decision to send him a letter that has since gone viral.
Spurs boss Mauricio Pochettino has conceded battling for players who command wage packets like Sanchez, or transfer fees like the £57m Manchester City are shelling out for Athletic Bilbao's Aymeric Laporte, is beyond him. In more recent times, United have won 33 of the teams' 51 Premier League encounters, with Spurs managing just seven wins and there have been 11 draws.