INDIANAPOLIS — Keenan Allen didn't sprint with the other wide receivers Sunday at the NFL scouting combine, but his brain has been getting a full workout in Indianapolis.
The 49ers were one of several teams that interviewed the talented Cal wideout and had him chart and analyze pass plays on a whiteboard.
"The 49ers grilled me really hard on it," said Allen, who met with receivers coach John Morton. "The coach was real strict and detailed, so I liked that a lot."
By the time the draft begins, the 49ers will have met with nearly every player on their draft board, and Allen will have been interviewed and dissected by every receiver-needy team in the league.
San Francisco has question marks at wide receiver.
Michael Crabtree is sure to start at one spot, but injuries and expiring contracts have created uncertainty at the other. On Friday, 49ers coach Jim Harbaugh said he didn't expect Mario Manningham, who suffered an ACL tear in late December, to be ready for the start of training camp. Kyle Williams also had a late-season ACL tear, and Randy Moss and Ted Ginn are unsigned.
Allen could slip into the second half of the first round because of his own knee injury, a posterior cruciate ligament tear in late October. The 6-foot-2, 210-pound wideout said he aggravated it while training for the combine but plans to work out for scouts at Cal's pro day on March 14.
Allen said he aims to quash concerns about his speed by running his 40-yard dash in 4.4 seconds.
While Allen is a big, physical receiver who must convince scouts he can stretch defenses, another potential target for the 49ers, West Virginia's Tavon Austin, has the opposite reputation.
At 5-8 and 174 pounds, Austin is one of the smallest players — kickers included — at the combine, and teams are wary of using high draft picks on players under 180 pounds.
But Austin also is one of the quickest and most aggressive, and he didn't shy away from comparisons to NFL stars Percy Harvin and Wes Welker.
Dana Holgorsen, Austin's coach at West Virginia, coached Welker at Texas Tech, and Austin said he was very familiar with the Patriots wideout.
"I feel like I'm a little quicker and faster than Wes," Austin said. "I feel like if he can do it, I can do it, too."
Austin said that like Harvin at Florida, he was used both as a receiver and a running back in college and can take a hit. He said he hasn't been injured in eight years. "I'm strong," Austin said. "A lot of people don't think I'm that strong, but I am. The No. 1 thing is my speed and how to set up a play."
Austin ran a 4.34 40-yard dash on Sunday, the second-fastest of the day. He has added attraction for teams such as the 49ers because he also is a prolific return man. If Ginn departs, the 49ers will lose their primary punt returner for the last three seasons.
Allen also returned punts at Cal. However, his attributes are his size and strength, and he likened himself to a big-bodied NFL receiver, Baltimore's Anquan Boldin, who gave the 49ers fits in the Super Bowl. Boldin led the Ravens with 104 receiving yards and a touchdown.