The highest-spending clubs were Liverpool (£165m), Chelsea (£120m), Fulham (£105m) and Leicester City (£100m), representing around 40% of the aggregate gross player transfer expenditure by Premier League clubs.
"My view is that it is hard for me to believe that we finished second", he said.
"The information I have is no".
Both clubs finished below United last season in the Premier League yet Mourinho claims they are projected as "serial winners" despite failing to land a trophy since 2012 and 2008 respectively. His side face Leicester City in their opening fixture at Old Trafford on Friday and it was put to Mourinho that there was a perception the club had gone backwards over the summer.
He said that he believes Liverpool will finish ahead of Manchester United in second place and Tottenham Hotspur will finish fourth despite a summer in which Mauricio Pochettino's team did not spend a penny in the transfer market. It is hard for me to understand we finish second.
"Is hard for me to understand, to feel, to believe we finish second - which I keep saying, and it is sometimes hard to believe, that I won eight championships and three Premier League's but I keep feeling the second last season was one of my biggest achievements in the game".
Colombia defender Mina, who impressed in the World Cup, could eventually cost €31.75million, while Gomes arrives on a season-long loan.
"Because it is very important their feeling and to understand how they think they can help or not help".
"In Championship Manager you can just press a button", he stated.
"[Alexis is] more than ready but you can not have the players who arrived only last Monday after the World Cup semi-finals or final and three weeks' holiday".