The goalkeeper has been deemed surplus to requirements at Real Madrid following the signing of Keylor Navas from Levante and is now poised to join the Rossoneri, having agreed personal terms with the Serie A side.
Lopez will undergo a medical in Milan on Monday before putting pen to paper on a four-year contract and Inzaghi is looking forward to working with the 32-year-old shot-stopper.
"The arrival of Diego Lopez is very important," he told reporters. "He's an experienced goalkeeper. He is going to improve our team."
Milan are also hoping to sign Adel Taarabt on a permanent basis, with the QPR-owned attacking having spent the second half of last season on loan at San Siro.
However, Inzaghi refused to be drawn on whether an agreement is close, saying nothing other than: "Will Taarabt be my gift for Ferragosto [an Italian holiday on August 15]? Let's see."
Although it appears as if the former Milan striker's squad looks set to be strengthened before the start of the Serie A season at the end of the month, Inzaghi is remaining grounded.
"I'm very happy," he stated. "Milan are doing things better. I want to do well together with the team.
"But only the field will tell us how well we can do. We must work hard and be ready for August 31."
Milan, who finished eighth in Serie A last season, kick off their campaign against Lazio at the Giuseppe Meazza.