Sure, three-fifths of the 49ers' projected starting offensive line is sitting out spring practices. But there's a flip side to that situation: Coaches have plenty of time to evaluate the back-ups.
And so far, Mike Nolan likes what he sees.
Third-year player Patrick Estes, for example, joined the 49ers in 2005 having played tight end for four seasons at the University of Virginia. As you would expect, Estes moved well but didn't have the necessary bulk for his conversion to left tackle. Now he is up to 310 pounds and has looked good in organized team activities while filling in for Jonas Jennings at left tackle.
"He's athletic, he's intelligent, and he's bulked up," Nolan said today. "He looks the part now."
Nolan said the true test for Estes will come in training camp, when players put on their padding and engage in full-contact practices.
Nolan also is anxious to see Damane Duckett, who has made an even more dramatic switch than Estes. The 6-6 Duckett played defensive tackle his first three years in the league but was moved to left tackle this spring.
Nolan said the conversion has been a success and that Duckett might be a good candidate for the practice squad.
* Darrell Jackson reported that his toe - he has a hyperextended left big toe - felt good this morning after running on it early in the week. Nolan said he expected Jackson will be ready for the team's first training-camp practice on July 29. When the 49ers signed the receiver in April they wanted to make sure he did all his rehabilitation in Santa Clara.
* Safety Mark Roman was excused from practice, and Keith Lewis filled in for him.
As expected, cornerback B.J. Tucker will miss the season with a torn pectoral muscle. The injury requires a four- to six-month rehabilitation.