SANTA CLARA, Calif. -- San Francisco 49ers quarterback Colin Kaepernick didn't get an opportunity to bounce back from a rough Wednesday practice on Thursday. That's because Kaepernick didn't participate in Thursday's practice.

A 49ers team spokesman said that Kaepernick took a "planned rest day" just 24 hours before the team shares a joint practice with the Houston Texans. Kaepernick did not throw during the workout, taking "ghost" reps behind quarterbacks Blaine Gabbert, Thad Lewis and Jeff Driskel and performing handoffs. That's similar to what he did in the spring as he recovered from shoulder, thumb and knee injuries.

Quarterback Blaine Gabbert took first-team reps while Colin Kaepernick sat out Thursday's practice. AP Photo/Ben Margot

It's been an up-and-down week for Kaepernick, who had a strong performance on Tuesday, particularly in seven-on-seven drills, then struggled Wednesday before sitting out Thursday. He also received some attention from trainers in Tuesday's practice when he spent time getting his right arm stretched out.

Gabbert took the bulk of the reps with the first-team offense. Considering Kaepernick didn't throw in the spring and is working his way back from those injuries, it's entirely possible he has some arm fatigue, so a day off would make sense.

It's unclear whether Kaepernick will practice Friday against the Texans. Coach Chip Kelly has said a decision on which quarterback will start the preseason opener against Houston will be made after the practice week is complete.

Other notes:

-- Defensive lineman Arik Armstead was back practicing after sitting out team drills the past couple of days with an apparent arm/shoulder issue. He had the arm wrapped for Thursday's session.

-- The 49ers kept Thursday's practice light, with no pads and a running time of about 70 minutes. That was to be expected after a couple of longer sessions Tuesday and Wednesday and in advance of what figures to be a more physical practice with the Texans on Sunday.

-- Gabbert didn't get many extra opportunities with Kaepernick out because it was such a short practice. He attempted just four passes in team drills, completing a deep attempt down the left sideline to Torrey Smith in seven-on-seven drills and hitting tight end Blake Bell for a touchdown during red-zone work. He also threw an interception on a deep pass intended for Bruce Ellington. Safety Eric Reid deflected the pass and safety Jaquiski Tartt made the diving interception.

-- The best (and only) tackle of the day came on the first play in team drills when an official got in running back Carlos Hyde's way and tripped Hyde. Both the official and Hyde went to the ground, but the official was worse for it. He had his knee wrapped in ice before finishing the practice.

-- Linebacker Ray-Ray Armstrong continues to show up in coverage, coming up with a nice pass breakup on a throw intended for running back Shaun Draughn. Armstrong is still battling for the inside-linebacker job next to NaVorro Bowman along with Gerald Hodges and Michael Wilhoite. Wilhoite practiced with the first team Thursday.

-- Rookie cornerback Will Redmond, who is expected to compete for the nickel job, got work there with the first team Thursday. ... Rookie guard Joshua Garnett continues to work on the left side after spending the first week on the right.

-- The 49ers and Texans are set to practice at 1:25 p.m. ET on Friday.