The Portuguese striker could be on the move again before the end of the transfer window, while the Serie A side are hopeful that Hernanes will not leave the club
The 68-year-old has made no secret of his desire to strengthen his squad since taking charge earlier in January and stated on Tuesday that the club are close to agreeing a deal to bring in the 31-year-old.
"We've been after Postiga for a week. He's got international experience and can play with [Miroslav] Klose," Reja told the press.
"We were about to finalise the deal [on Monday] night and I'll be particularly happy if Postiga arrives."
Reja is also hopeful of keeping hold of midfielder Hernanes, who has been strongly linked with Serie A rivals Inter.
"We have options if Hernanes does go," he remarked, "but I don't think he's leaving."
The 28-year-old Brazilian has a contract with Lazio until June 2015.