That is, however, exactly the task facing Geoff Cross when he steps out at Murrayfield tomorrow, making only his third start in a season where he has been pretty much discarded from Edinburgh's plans.
No wonder, then, that he was non-committal on the subject of whether he would be staying. "I haven't arranged a contract with Edinburgh and I haven't arranged a contract with anyone else. Those are the facts. Watch this space," was all he would say, but it is clear that something has to change if he is to keep adding to his 26 caps and make it through to the Rugby World Cup next year.
He has played in four games for Scotland this season, all from the bench, and eight for Edinburgh, two starts and six coming on as a replacement. In two games - 42 minutes against Italy two weeks ago and 69 last week against the Ospreys - he came close to doubling his season's game time despite being in the matchday squads for 23 club and international matches.
Whether that is anywhere near enough to give him the match fitness he needs to tackle Thomas Domingo, the French loosehead and a renowned scrummager, will be demonstrated tomorrow but asking him to shoulder the burden is a gamble for Scott Johnson, the interim Scotland coach.
He can argue, with justification, that he has no real choice. Moray Low had to be removed from the Italy game before half time and Euan Murray is even rustier than Cross after picking up an Achilles' tendon injury and then a cutting his hand chopping wood — an "axe-ident" to use Murray's own pun. The only match-sharp and in-form tighthead prop in Scottish rugby is Willem Nel, who, as yet, is not "Scottish".
Cross acknowledges it is an isssue, but says he is doing all he can to rectify it. "You would have to speak to the selectors about why they pick people they do," he said. "The things that I look at, and how I compare myself to other tightheads, is to ask: how is my scrummaging, my other set piece, my defensive work? Am I getting into the right position to make tackles? Are the tackles good? Am I doing the right thing afterwards? Do I lie on the ground doing nothing, or do I spring back up?
"Then there are things around structures of play: am I in the line, listening and talking to other guys? That's what I look at. I enjoy playing but you are a tool for the selectors to use. If they choose not to, then that's the position you are in and the important thing is to keep working. I now have the chance to prepare for an exciting game against France, and that's what I'm thinking about now."