The Red Devils are in second place in the Premier League table but Manchester United are 16 points behind leaders Manchester City.
The 20-time English champions lost 2-1 to La Liga giants Sevilla in the second leg of their Champions League last-16 clash.
Manchester United can still finish the season with some silverware if the Red Devils win the FA Cup at Wembley.
Mourinho’s men will have to get past Tottenham Hotspur in the semi-finals to win the competition for the second time in three seasons.
Manchester United have spent over £300m on eight players since Mourinho took over the reins from Louis van Gaal in May 2016.
Former Liverpool FC defender Thompson believes Mourinho hasn’t made enough progress at Manchester United.
“I would say yes they are making progress, but not greatly, especially for the money spent to assemble it,” Thompson told Sky Sports.
“I can’t say Mourinho has really turned this around and they should be doing better all considered.
“We can’t forget he won two trophies last season and has a chance at winning the FA Cup this campaign, while the style of football has changed since Louis van Gaal and is a bit better watch. But I don’t think it is the Manchester United way still.
“If you get results, everyone is happy. But if they don’t get those results, the questions will come, although he is the best in the world at deflecting the tension.”
Manchester United signed Alexis Sanchez in a swap deal from Arsenal in the January transfer window.
However, the South American forward has scored one goal in 10 appearances in all competitions since his move to Old Trafford.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news