Again, his stats show he is up there with the best. People remember the mistakes bit few remember the crucial tackles or the ones which start a key attack.
You know how many players we've bought based on stats and who were shipped away after a season or 2. For instance you can have a very high stats on passing the ball, but you usually do it sideways and to the back without taking any risks. United has one of the highest possession under Van Gaal, but without being offensive.
Yes, stats can be deceiving but I feel Lucas is very underrated. As a matter of fact, you mention passing sideways but take a look at his stats and you'll find that he has the highest number of KEY passes per game of all the Premier League defensive mids. That means he isn't only passing the ball sideways and backwards.
Also, he has been quite a bit more attacking under Klopp.
Last but not least, if Rafael Benitez, Kenny Dalglish and Jurgen Klopp feel there is no need to replace him and feel that he is good enough for our starting line up, there has to be a decent player in there.
I just feel he is underrated and was a bargain might I add. Are Schweinsteiger, Schneiderlin, Matic, Mikel, Fernandina really performing any better than Lucas. I don't think so.
I feel the simple fact that when Lucas has a poor game it influences our play so much, says volumes about how important he really is to our overall play. Look at our win/lose rates with and without him in the team.