The 49ers’ offensive line made significant strides once Adam Snyder took over at right guard three games into last season.

Now the 49ers must replace Snyder, who signed a five-year contract Wednesday with a division rival, the Arizona Cardinals. Financial terms were not disclosed.

“I loved it there,” Snyder said of the 49ers to the Arizona Republic. “But at this point in my career, I was ready for something else.”

Aside from finding a new starting right guard, the 49ers remain on the prowl for wide receivers.

Mario Manningham, who made clutch catches in the New York Giants’ Super Bowl run, is slated to visit the 49ers facility Thursday, according to ProFootballTalk.com. Fellow free-agent receivers Brandon Lloyd and Chaz Schilens were guests Wednesday.

Snyder, whose wife is from the Phoenix area, signed with the Cardinals shortly upon his visit Wednesday.

Among the 49ers’ next options at right guard: a) Draft a ready-made prospect, such as Stanford’s David DeCastro; b) Promote Daniel Kilgore, a fifth-round pick last year; c) Re-sign free agent Chilo Rachal; d) Sign a free agent such as 11-year veteran Leonard Davis, who reportedly visited the 49ers on Wednesday.

Snyder is coming off his best season with the 49ers, who drafted him in the third round in 2005. After auditioning for the first time at center in training camp, he flourished at right guard upon replacing Rachal at halftime in a Week 3 win over Cincinnati.

Of Snyder’s 69 career starts, he made 21 at left tackle, 21 at right tackle, 17 at right guard and 10 at left guard. He also subbed in for six snaps at center in last season’s playoff win over New Orleans.

Snyder’s swan song came in the NFC Championship game, a 20-17 overtime loss in which Manningham made a fourth-quarter touchdown catch to spark a comeback.

The 49ers’ receiving corps has been under construction all week: Randy Moss ditched retirement for a one-year contract, Joshua Morgan signed with the Washington Redskins and Ted Ginn Jr. is checking out the Detroit Lions, according to MLive.com.

Manningham, a four-year veteran, made a sensational sideline catch in Super Bowl XLVI to launch the Giants’ game-winning touchdown drive against New England. He caught a touchdown pass in each of their three earlier playoff victories.

The 49ers have made no secret of a desire to upgrade their 29th-ranked passing attack. But they’re doing so with quarterback Alex Smith unsigned. Smith said last weekend the final details of a deal were being completed, and 49ers CEO Jed York on Monday put the onus on Smith to accept the 49ers’ offer.

Running back Frank Gore, in a phone interview with the Associated Press, said he’s “excited” over the 49ers’ recent moves but wants Smith’s deal done, too.

“He went through a whole lot, man,” Gore said.

For more on the 49ers, see Cam Inman’s Hot Read blog at blogs.mercurynews.com/49ers.