Earlier in free agency former San Francisco 49ers guard Mike Iupati signed with the Arizona Cardinals. Today the team released offensive tackle Jonathan Martin. Does this indicate they'll be drafting an o-lineman with the No. 15 overall pick?

Offensive tackles Andrus Peat and Ereck Flowers could be available by the time they draft, but the Niners have to deal with a specific aspect of their offensive line.

San Francisco dealt with a slew of injuries on the O-line in 2014, but they still managed to finish 9th overall in Pro Football Focus' Offensive Line Rankings (16th in pass and 5th in run). Even though Martin wasn't a very effective right tackle, he still provided solid depth and started nine games with Anthony Davis sidelined with injuries. Iupati was one of the top guards in the league and missed only five games in five seasons with the team.

Here's the Pro Football Focus breakdown:

"Stud: The usual drill with the 49ers as the excellent Joe Staley had another Top-5 left tackle season, finishing fourth in our rankings."

"Dud: Rookie's often come into the league and struggle and Marcus Martin was no different there. He was pushed about frequently."

"Breakdown: As is often the case in San Francisco, they are a bullying group of linemen who can impose themselves in the run game, but are susceptible to giving up quick pressure. No difference this year with free agent-to-be Mike Iupati epitomizing this."

With an obvious need to patch up the interior line, it doesn't look like they'll be able to address that in the first round. Peat and Flowers check out as solid exterior lineman at both the left and right tackle positions, and San Francisco has Staley and Davis already signed to long-term deals. However, could Peat be a potential option to play guard and replace Iupati?

"Peat has good length, a strong anchor, a powerful upper body and excellent overall agility in pass protection. As a run-blocker, he has the power base to drive defenders off the ball. What really stands out on tape is his foot quickness," writes ESPN Insider Todd McShay.

"Where he'll get himself in trouble is in giving too much respect to good speed-rushers and losing the fundamentals. Peat can show impressive power going downhill and he'll de-cleat a defender when he gets to turn inside and block down," adds ESPN Insider Mel Kiper Jr.

With his various capabilities as a lineman, coupled with the potential weaknesses the scouts are foreseeing, is it possible the 49ers draft Peat and put him at guard? After all, he did run a fairly quick 40-yard dash time (4.18) at the NFL Combine, which was faster than most of the guards. Peat has the athleticism to be a Swiss army knife offensive lineman.

The 49ers have needs on the defensive side of the ball, but bolstering the offensive line is perhaps most important, especially after the question marks that arose last season when various injuries occurred.