After talking to Mason on Tuesday, Harbaugh said it was clear that the receiver's announcement "wasn't a tactic of any kind."
"We love him and care about him," Harbaugh said. "I told him that we want him on our team but we respect his decision either way."
Even if Mason changes his mind, Harbaugh said the Ravens would add another veteran "if we can find the right guy." According to a team source, the two most recognizable names for today's four-player tryout are Bennett and D.J. Hackett.
Bennett, 30, has averaged 14.4 yards per catch for his career and could become a deep threat for Flacco. The biggest question is Bennett's health. He had only one reception last season for the St. Louis Rams after injuring his foot in the season opener.
Hackett, 28, has averaged nearly 30 catches a season, but there's a question of whether he would fit with the Ravens because he's worked predominantly in West Coast offenses.
"There are some options out there that could possibly help us," Harbaugh said.
Mason, 35, has been the team's most dependable receiver, leading the Ravens in catches during three of his four seasons with them. Since he left the Tennessee Titans to join the Ravens, Mason has recorded the three highest single-season totals for catches (103 in 2007, 86 in 2005 and 80 in 2008).
Without Mason, the Ravens have a void at receiver. The top four receivers on the roster - Mark Clayton, Demetrius Williams, Marcus Smith and Kelley Washington - combined for 55 catches and four touchdowns last season.
"I think Derrick will give us an honest decision," Harbaugh said. "If he comes back, it will be full-go, 100 percent. If he doesn't, it'll be full-go, 100 percent into the next phase of his life. He's kind of at a fork in the road, and he wants to make the best possible decision."
Baltimore Sun columnist Mike Preston contributed to this article.
