SANTA CLARA – The 49ers doubled up on only one position, outside linebacker, during the recent draft because they had so few players at the position last season. Now both of those draft picks are out with injuries.

Coach Jim Harbaugh on Tuesday said seventh-round pick Cam Johnson had a "clean-out" procedure that is not expected to keep him out of training camp. Harbaugh would not discuss the specific injury, but Johnson's most recent coach, Virginia's Mike London, said last month that Johnson pushed through a knee problem – including what London termed a "bone-on-bone situation" – as a senior last year.

Harbaugh did say that Johnson was having difficulty in the recent organized team activity practices and that the goal was to address it now so that the rookie will be pain-free when training camp begins in late July.

"I think it was hindering him early in OTAs and minicamp," Harbaugh said.

The 49ers' other draft pick at outside linebacker, fifth-round selection Darius Fleming, tore a ligament during a rookie minicamp last month. Although he hasn't been placed on injured reserve, Fleming is a long shot to play this season.

The only outside linebackers on the roster last season were Ahmad Brooks, Parys Haralson and Aldon Smith. Smith and Brooks have been playing with the first-team defense, while Haralson and Eric Bakhtiari, who played for Harbaugh at San Diego, were with the second team. The 49ers also signed undrafted free agent Kourtnei Brown, who was a defensive end at Clemson.

Johnson's situation is reminiscent of last year when then-rookie Colin Kaepernick opted to have a minor procedure during the lockout so he'd be healthy for training camp.

Two-way player – One of the highlights of Tuesday's practice was 293-pound Will Tukuafu catching a swing pass from quarterback Alex Smith and then racing inside linebacker Patrick Willis to the corner of the end zone for a touchdown.

Tukuafu's primary position is defensive end, but he has exclusively played fullback in the two practices – last week and Tuesday – that have been open to the media.

He seems to have potential as a three-way player. Tukuafu began last season on the 53-man squad and had a sizable role on special teams, where he suffered a broken wrist that cost him the season.

Tukuafu showed nice finesse in the recent non-padded practices. But Harbaugh said there's more to come.

"Will's doing a great job, athletically," he said. "I think the best will come when he puts on the pads, and that's when it will get really exciting and fun."

Et cetera – Cornerbacks Carlos Rogers and Curtis Holcomb, wide receiver Ted Ginn and rookie guard Joe Looney spent the practice rehabilitating various undisclosed injuries. All four were seen sprinting, usually one of the last stages before they rejoin practice.

• Harbaugh cited tight end Vernon Davis as one of the standouts from the spring practices. "He's having an outstanding offseason, every day, just getting better at route running – every facet of the position," Harbaugh said.

• This is the final week of OTAs. The team will have a mandatory minicamp next week.

© Copyright The Sacramento Bee. All rights reserved.

• Read more articles by Matthew Barrows

Order Reprint