The following seasons were not so successful, but Inzaghi did help Lazio conquer another Coppa Italia, in 2003–04; in September of that year, he extended his contract until June 2009. Inzaghi spent the latter half of the 2004–05 season with Sampdoria, as part of a six-month player exchange with Fabio Bazzani. He returned to Lazio for the 2005–06 campaign and stayed for the following, with only 12 appearances combined. The following season, Inzaghi joined Atalanta on loan. Although he struggled to find his form early on, he managed to play in 19 league matches, mostly as a second-half substitute, but did not find the net.