The forward signed a six-month loan deal in the summer at the Championship club and he does not know where his next move will be.
Armstrong may return to St James’ Park but he has impressed while on loan at Bolton and he has already made 18 appearances for the Trotters.
Despite only enjoying a brief spell under Benitez, the 20-year-old has been full of praise for the Spaniard and he is excited to work under him in the future.
He told Bolton’s official matchday programme: “Rafa is a brilliant manager who has worked with some of the best players in the world.
“He’s just got a presence when he is stood in front of you, you can’t help but be taken in by.
“I’m enjoying my football at the moment. I’ve already seen an improvement in my game but I’m taking it each match as it comes. You can’t think too far ahead in football because it changes in an instant.”
A goal apiece from James Tomkins and Luka Milivojevic handed Crystal Palace a crucial 2-0 win over Huddersfield at the John Smith's Stadium on Saturday evening.
Manchester United bounced back from their Champions League exit as they beat Brighton 2-0 at Old Trafford on Saturday night to reach the FA Cup semi-finals.
Tottenham reached the FA Cup semi-finals after they cruised to a 3-0 victory over Swansea in their quarter-final clash at the Liberty Stadium on Saturday.
Premier League basement club West Brom squandered the lead as they suffered a 2-1 defeat to Bournemouth at the Vitality Stadium on Saturday.
Chesterfield boss Jack Lester felt his side were unlucky not to claim all three points after their 1-1 draw at Cheltenham.
New Swindon manager Phil Brown revelled in his side's victory at Cambridge in his first game in charge.